The conventional view holds that girih (geometric star-and-polygon) patterns in medieval Islamic architecture were conceived by their designers as a network of zigzagging lines, where the lines were drafted directly with a straightedge and a compass. We show that by 1200 C.E.
Girih tiles are a set of five tiles that were historically used in the creation of ornaments for decoration of buildings in Islamic architecture. This browser app allows you to:
- Lay Girih patterns on an infinite canvas.
- Color and style your design.
- Export as vector images.
Girih tiles are a set of five tiles that were used in the creation of Islamic geometric patterns using strapwork ( girih) for decoration of buildings in Islamic architecture. They have been used since about the year 1200 and their arrangements found significant improvement starting with the Darb-i Imam shrine in Isfahan in Iran built in 1453.
With shiftr.io you can easily interconnect your objects, devices and apps.
Tsubaki Abura – Camellia Oil
Camellia oil is applied to the barengawa (the bamboo sheath on a baren) to keep it supple and prolong its life. The oil may be applied with a saturated pad, cotton ball, or use the palm of your hand. Rub just a drop or two of oil into the sheath, paying attention to the sides as well as the face of the barengawa.
Imported from Japan, our camellia oil comes from camellia japonica seeds. It is cosmetic grade and used in Japan as a hair and skin moisturizer, so it is good for your skin as well the barengawa.
The oil will also protect cutting tools from rust. Apply a small amount to the steel blade after sharpening it on water stones.
This high tech plastic baren was designed by the famous Japanese relief printmaker, Akira Kurosaki. The replaceable disc has tiny bumps on the surface that apply pressure evenly across the paper as you print. When these bumps wear down after extended use, you can simply remove the old disc and press on a new one.
This neutral pH rice starch powder is made from glutinous rice, so mixing and
cooking it on the stove is not necessary. If your tap water has a high mineral content, use distilled water instead.
1. Place 3 tablespoons of rice starch powder in 1 cup of boiling water.
2. Stir briskly with a wire whisk until smooth. If there are lumps left, pour the hot mixture through a strainer and discard the lumps.
3. Cool before using. The rice paste will thicken as it cools. This recipe will produce a paste that is about the consistency of heavy cream or yogurt.
For a thicker paste, use 4 tablespoons of rice starch; for a thinner paste, use 2 tablespoons.
If you prefer to cook the paste, this recipe is from The Art & Craft of Woodblock Printmaking.
1. Mix 2 tablespoons of rice starch with 5 dl (3½ tablespoons) cold water
2. Stir until smooth and milky
3. Bring 150ml (2/3 cup) of water almost to the boil
4. Add the paste mix in a smooth ribbon while stirring
5. Bring to a boil and keep stirring constantly until the mix goes translucent (about five minutes)
6. Cool, stirring from time to time
The mixture will thicken as it cools. If it is too thick, thin with water. If it is too thin, make a new mixture
but this time make it extra thick so you can add it to the first mixture. Combining the two will give the
Nori is very important in the Japanese style of printmaking. It works as a dispersing agent to give the ink body so it will spread evenly over the block. Ink without nori can look speckled when it is printed, often an unwanted effect, while ink with nori prints more uniformly. Traditionally, it is also used to paste the original drawing to the block.
Nori can be used for chine collé, book repair, and everyday paper pasting jobs. It is smooth, has a pleasant scent, and will not stain. Water reversible, nori is acid free, strong, and because it contains a very tiny amount of formalin, it does not spoil.
If you prefer to make your own rice paste, we also carry Pure Rice Starch.
seen at McClain´s Printmaking Supplies
The kento is a simple device by means of which the printer insures the register of the picture throughout the printing process. It has been employed for several centuries, and experience has proved it to be the best means for the purpose. The principle is to maintain with absolute exactness the width of the margin of every requisite block by means of two small projections, the kagi (key) and the hikitsuke (draw stop), which are cut directly on the block, as shown in Figure 1. These guides cut on the key block will be printed on the kyogo (proofs pulled from the key block) and therefore copies on every color block, keeping the margin the same width as that of the key block. The printer positions his paper so that its edges coincide with these guides during printing. The kagi is a right-angled guide at the lower right-hand corner of the block; the hikitsuke, a straight-line guide…at a short distance from the lower left-hand corner. To cut these guides, the carver uses the kento-nomi,(a 15mm chisel) the edge of which is strongly made with a wider angle and is perfectly straight. The kento-nomi is held by the grip in the right hand, resting upright on the board with its edge exactly at the line to be cut, in such a manner that the flat side of the tools is vertical to the surface of the board (Figure 2). Then it is pressed down to make a cut about one-eighteenth of an inch deep. After the necessary lines have been cut in this way, the space must be cleared with an aisuki(bull-nose chisel) of large size. The clearing must be very shallow and must produce a flat and smooth surface in order to facilitate the fitting of the paper during printing. The depth required is two to three times the thickness of the paper to be used. In making the kagi, the cleared part must slope very slightly toward the point of the right-angled corner. The hikitsuke is left in the form of a sort of step, the top of which is cut in a straight line. The detail of these two guides can be seen in Figure 3a and 3b.
Re-printed from Japanese Print-Making by Toshi Yoshida and Rei Yuki, c. 1966
Find great deals for Pl2303ta USB TTL to Rs232 Converter Serial Cable Module for Win 8 XP Vista 7 8.1. Shop with confidence on eBay!
IT is born to make the brain of LEGO ® EV3 much more BETTER, both the hardware and the software. The EVB which is based on the famous platform of Beaglebone Black to meet your exceptional needs that EV3 can not do.
SBrick Plus is a brick that you can place into your LEGO® models so you can control them remotely using a smart device like a phone, tablet, gamepad or even Chromebook or PC.
BrickPi is a robot kit that connects your LEGO MINDSTORMS EV3/NXT sensors and motors to the Raspberry Pi and program in Scratch, Java, Python and more.
Get started using EV3 Python to control your Lego EV3 robot!
PiStorms LEGO Mindstorm with Raspberry Pi Brains
New! Pixy for LEGO Mindstorms Fast vision sensor for LEGO robotics Easily “teach” Pixy objects to track Connects directly to NXT or EV3 brick Pixy (CMUcam5) Fast vision sensor for robotics Easily “teach” Pixy objects to track Connects directly to Arduino Pan/Tilt Kit for Pixy Dual servos provide X-Y movement Great “Hello world” demo for …
leJOS is a Java based replacement firmware for the Lego Mindstorms RCX microcontroller and NXJ is a Java based replacement firmware for the Lego Mindstorms NXT microcontroller
Based on Makeblock open platform, mDrawBot is a transformable drawing robot kit that integrates mechanics, electronics, software, and art. It can be assembled into four forms: mScara(Cylindrical Coordinates Robotic Arm), mSpider(Wall-Drawing Machine), mEggBot(Egg-Painting Robot), mCar(Drawing Car).
Based on Makeblock open platform, mDrawBot is a transformable drawing robot kit that integrates mechanics and electronics via the easy-to-use software mDraw.
mScara (Cylindrical Coordinates Robotic Arm)
mSpider (Wall-Drawing Machine)
mEggBot (Egg-Painting Robot)
mCar (Drawing Car).
This library allows you to control unipolar or bipolar stepper motors. To use it you will need a stepper motor, and the appropriate hardware to control it. For more on that, see Tom Igoe’s notes on steppers.
Detailed ZYLtech CNC Shield Instructions, including “First Run”, Current Limit Adjustment for Stepper Driver, Jumper Settings, and Motor Wiring.
This is a quick guide to help with assembling the Arduino CNC Shield V3.XX. We also have a discussion forum for this board : http://forum.protoneer.co.nz/viewforum.php?f=6 Contents: First step is to solder the Power Wire( or Fuse) and 10K (R1) resistor in place. (Version 3.03 and on does not need the Power Wire anymore.)
Acronym for computer-aided design
FREQUENTLY ASKED QUESTIONS:
Woodworking software for 3D reliefs, decorative woodwork and CNC machining
Autodesk ArtCAM woodworking software is a solution for designing and making decorative woodwork. Create furniture, 3D reliefs, signs and gifts using a CNC machine.
connecting amazon echo to devices + internet scripts
Pre-loaded with the latest GRBL firmware v1.1. GRBL V1.1 PWM compatible. (Open source firmware that turns G-code commands into stepper signals). Uses removable Pololu A4988 compatible stepper drivers. | eBay!
DRV8825 allows higher resolutions by allowing intermediate step locations, which are achieved by energizing the coils with intermediate current levels. The resolution (step size) selector inputs (MODE0, MODE1, and MODE2) enable selection from the six step resolutions according to the table below:
- Simple step and direction control interface
- Six different step resolutions: full-step, half-step, 1/4-step, 1/8-step, 1/16-step, and 1/32-step
- Adjustable current control lets you set the maximum current output with a potentiometer, which lets you use voltages above your stepper motor’s rated voltage to achieve higher step rates
- Intelligent chopping control that automatically selects the correct current decay mode (fast decay or slow decay)
- 45 V maximum supply voltage
- Built-in regulator (no external logic voltage supply needed)
- Can interface directly with 3.3 V and 5 V systems
- Over-temperature thermal shutdown, over-current shutdown, and under-voltage lockout
- Short-to-ground and shorted-load protection
5 Line 4 phase can be driven by ordinary uln2003 chip can also be connected in phase 2 development board used for. Stepper motor driver board with ULN2003. 1 ULN2003 Drive Test Module Board. This board motor kit supports you to use a direct plug and make it easy to use stepper motor used in the development board.
A) grbl-controller 3.0
Grbl Controller sends GCode to CNC machines. Version 3.0 is has been optimized for the Arduino to control Grbl shields. Grbl Controller can use the QextSerialPort library to simplify choosing the correct USB serial port.
MakerCAM is a web based CAM program. Simple by design, MakerCAM allows you to produce toolpaths for 3-axis CNC machines that accept standard RS274D GCode.
link: Getting started tutorial
link: about makercam
C) Easy cnc
The goal of the project is the realization of a modular firmware that allows to control a CNC machine with different utensils.
A small program to quickly generate GCode. It can generate circular pockets, square pockets, etc. Now you can generate a simple program from DXF.
Use the tab “Cutting a path” or “Array of elements”. Added engraving by DXF file.
E) gcodetools – inkscape plugin
F) JSCUT – a cam in your browser
|GCode Ripper||Wrap GCode for 4th Axis or do Engraving on Irregular Surfaces after Probing|
|LinuxCNC / EMC2||Free CNC Control Software|
|Jedicut||CNC Foam Cutting|
|Ace Converter||DXF to G-Code|
|2linc Engraving Software: Light Version||Engraving Software
|Image to G-Code||Image or bitmap to g-code|
grbl on python: pyGerber2Gcode
3 x 4 Pin Dupont Female Connectors
GRBL firmware http://www.ebay.com/itm/Arduino-CNC-Shield-V3-10-G…
The Pi Cap adds precise capacitive touch, proximity sensing and high quality audio to your Raspberry Pi.
Connect your Pi project to the physical world. Create sensors by connecting Electric Paint or anything conductive to one of the Pi Cap’s 12 electrodes to control audio, video or connect to the internet. Make a MIDI piano, an interactive wall, a proximity sensor — you decide. Our Raspbian package contains code examples for C++, Python and Node.js.
• Capacitive touch and distance sensing
• High quality audio output
• Tutorials to help you get started
• User-programmable RGB LED
• Multi function button
• Prototyping area with GPIO breakout
• Compatible with Raspberry Pi A+, B+, Zero (or any Pi with 40 pin GPIO connector)
• Powerful C++, Python and Node.js libraries and examples
Crocodile clips, copper tape, solder and e‐textiles. Use with Electric Paint to design your own sensors
Control Servos + PWM devices using this 16 channel PWM Expansion Board. PCA9685
When you run out of PWM Arduino-pins or are on a Raspberry Pi that doesn’t have PWM capability. With this PWM Expansion Board you can control up to 16 PWM driven devices from via 2 I2C pins. Can also be daisy-chained to give you up to 992 PWM outputs.
- I2C controlled PWM/Servo driver board
- Clock on board
- Operating Voltage: 3.3V – 6V
- 6 I2C Address Select Pins
- Max Daisy-chaining: 62 boards for a total of 992 PWM outputs
- Max PWM frequency: 1.6 kHz
- Resolution: 12 bit
- Configurable Output (push-pull or open-drain)
- Output Enable (OE) allows you to turn off all outputs at once
- Onboard Features:
- Polarity Protection
- Power Indicator LED
- Optional capacitor solder point for smoothing
- Address Select Jumpers
INSTALL WORKFLOW using an arduino uno and an arduino cnc shield:
1) Grbl is a motion control GCode Interpreter. The controller is written in highly optimized C to achieve precise timing and asynchronous operation. It is able to maintain up to 30kHz of stable, jitter free control pulses.
download GRBL 1.1 here
get inspired from some nice examples from the original author
NEMA 17 – 12V – four-phase unipolar permanent-magnet stepper-motor
1.8° full step – 200 steps-per-revolution
0.9° half-step – 400 steps-per-revolution
NEMA chose to label stepper motors (e.g. “NEMA 17”) with the size of their faceplate in tenth of inches. So a “NEMA 17” has a 1.7 inch by 1.7 inch faceplate. By standardizing the stepper motors (the faceplates, flanges and screw holes), you know ahead of time that one NEMA 17 motor will fit into the mounts of another NEMA 17 without having to redesign anything. This makes swapping components easier.
1.5 kg-cm 6 Wire NEMA 17 Stepper Motor – Item no. 42BYGH34-04
12VDC, Rated current 1.3A, 500rpm, Torque 0.26NM, size: 42x42x34mm
17HS1352-P4130 – hybrid
2.2 kg-cm 6 Wire NEMA 17 Stepper Motor
12-24VDC, Rated current 1.33A, 500rpm, Torque 0.26NM, size: 42x42x34mm
1.7A – 1.8degrees
42BYGHW609D4P1 Stepper Motor (Makeblock 81042)
PHASE : 2PHASE
STEP ANGLE : 1.8+-5%°/STEP
RATED VOLTAGE : 12V
CURRENT : 1.7A/PHASE
RESISRANCE : 1.5+-10%/PHASE
INDUCRANCE : 2.8+-20%mH/PHASE
HOLDING TORQUE : 40N.cm Min
DERENT TORQUE : 2.2N.cm Max
INSULATION CLASS : B
LEAD STYLE : AWG26 UL1007
ROTOR TORQUE : 54G.cm2
Grbl is a no-compromise, high performance, low cost alternative to parallel-port-based motion control for CNC milling. It will run on a vanilla Arduino (Duemillanove/Uno) as long as it sports an Atmega 328.
The controller is written in highly optimized C utilizing every clever feature of the AVR-chips to achieve precise timing and asynchronous operation. It is able to maintain up to 30kHz of stable, jitter free control pulses.
It accepts standards-compliant g-code and has been tested with the output of several CAM tools with no problems. Arcs, circles and helical motion are fully supported, as well as, all other primary g-code commands. Macro functions, variables, and most canned cycles are not supported, but we think GUIs can do a much better job at translating them into straight g-code anyhow.
Grbl includes full acceleration management with look ahead. That means the controller will look up to 18 motions into the future and plan its velocities ahead to deliver smooth acceleration and jerk-free cornering.
Pololu A4988 compatible stepper drivers. (A4988, DRV8825 and others)
The A4988 is a microstepping driver for controlling bipolar stepper motors which has built-in translator for easy operation.
Microstepping can divide a motor’s basic step up to 256 times. Microstepping improves low speed smoothness and minimizes low speed resonance effects.
Microstepping produces roughly 30% less torque than dual phase full stepping
- GRBL 0.8c compatible. (Open source firmware that runs on an Arduino UNO that turns G-code commands into stepper signals https://github.com/grbl/grbl)
- 4-Axis support (X, Y, Z , A-Can duplicate X,Y,Z or do a full 4th axis with custom firmware using pins D12 and D13)
- 2 x End stops for each axis (6 in total)
- Spindle enable and direction
- Coolant enable
- Uses removable Pololu A4988 compatible stepper drivers. (or DRV8825)
- Jumpers to set the Micro-Stepping for the stepper drivers. (max 1/16)
(The DRV8825 board can do up to 1/32 micro-stepping)
- Stepper Motors can be connected with 4 pin molex connectors.
- Runs on 12-36V DC. (Only the Pololu DRV8825 can handle up to 36V)
Using two jumpers the 4th axis can be configured to clone the X or Y or Z axis. It can also run as an individual axis by using Digital Pin 12 for Stepping signal and Digital Pin 13 as direction signal. (GRBL only supports 3 axis’s at the moment)
Clone X-Axis to the 4th stepper driver(Marked as A)
Clone Y-Axis to the 4th stepper driver(Marked as A)
Clone Z-Axis to the 4th stepper driver(Marked as A)
Use D12 and D13 to drive the 4th stepper driver(Marked as A)
End Stop Configuration
By default GRBL is configured to trigger an alert if an end-stop goes low(Gets grounded). On the forums this has been much debated and some people requested to have active High end-stops. The jumpers in the picture provides the option to do both. (To run with default setting on GRBL the jumper need to be connected like the left shield in the image below)(This Jumper was only introduced in Version 3.02)
End-stop switches are standard “always open” switches. An End-stop gets activated when the end-stop pin connects to ground(When setup with default GRBL settings).
Configuring Micro Stepping for Each Axis
Each axis has 3 jumpers that can be set to configure the micro stepping for the axis.
In the tables below High indicates that a Jumper is insert and Low indicates that no jumper is inserted.
- Operating Voltage: 5V
- 5 Push buttons to supply a custom menu control panel
- RST button for resetting arduino program
- Integrate a potentiometer for adjusting the backlight
- Pin used:
- D4-D7 -> LCD Data transmission
- D8 -> Register Select
- D9 -> Enable pin
- D10 -> Backlight control
- APC&BT pin header for connecting wireless devices, directly compatible with:
- Expanded available I/O pins
- Expanded Analog Pinout with standard DFRobot configuration for fast sensor extension
- Dimension: 80 x 58 mm (3.15x 2.28 in)
brew install python
brew link python
brew install python3
brew link python3
rm -rf mydir
pu pen up
pd pen down
repeat 4 [fd 90 lr 90]
10 bright green
11 dark blue
TO RANDOM.MOVE (D1, D2, A1, A2)
LEFT RAND (A1, A2)
FORWARD RAND (D1, D2)
TO CHECK.FORWARD DISTANCE
OLD.POSIITON = TURTLE.STATE
FORWARD.FAILED = OUT.OF.BOUNDS?
POTS (That’s short for Print Out TitleS.)
brew install node
npm install -g npm@latest
npm i -g n && n latest
(Node package manager)
(nvm install node –reinstall-packages-from=node)
brew update && brew upgrade node && npm install -g npm
1. sudo npm cache clean -f ———— (force) clear you npm cache
2. sudo npm install -g n ———install n (this might take a while)
3. sudo n stable ——— upgrade to lastest version
You could install nvm and have multiple versions of Node.js installed.
curl https://raw.github.com/creationix/nvm/master/install.sh | sh
and then run:
nvm install 0.8.22 #(or whatever version of Node.js you want)
you can see what versions you have installed with :
and you can change between versions with:
nvm use 0.8.22
The great thing about using NVM is that you can test different versions alongside one another. If different apps require different versions of Node.js, you can run them both.
If your devices has 1Mbyte or more of storage then it will be set up (upon first boot) to contain a filesystem. This filesystem uses the FAT format and is stored in the flash after the MicroPython firmware.
pip install esptool
esptool.py –port /dev/tty.wchusbserialfd120 erase_flash
esptool.py –port /dev/tty.wchusbserialfa130 erase_flash
CD DOWNLOAD FOLDER:
esptool.py –port /dev/tty.wchusbserialfd120 –baud 460800 write_flash –flash_size=detect 0 esp8266-20170823-v1.9.2.bin
esptool.py –port /dev/tty.wchusbserialfa130 –baud 460800 write_flash –flash_size=detect 0 esp8266-20170904-v1.9.2-41-g9950865c.bin
boot.py – main-py
screen /dev/cu.wchusbserialfa130 115200 (WEMOS MINI)
screen /dev/cu.wchusbserialfd120 115200
(initialize:) import webrepl_setup
(assign password) allow acces
>>> print(‘hello esp8266!’)
>>> import machine
>>> pin = machine.Pin(2, machine.Pin.OUT)
>>> def toggle(p):
… p.value(not p.value())
(enter 3 times exits)
>>> import time
>>> while True:
PASTE MODE: Ctrl-E
paste mode; Ctrl-C to cancel, Ctrl-D to finish
>>> f = open(‘data.txt’, ‘w’)
>>> f.write(‘some data’)
>>> f = open(‘data.txt’)
>>> import os
This is an amazing ressource for learning advanced Processing (and p5)
Download the entire book directly from the author.
arduino board som lader dig kommunikere via din Smartphone (ios & android)
ESP-WROOM-32 ESP32 ESP32S IoT Wifi Wlan BLE Module+Adapter Board
|Four faces||Six faces||Eight faces||Twelve faces||Twenty faces|
|Polyhedron||Vertices||Edges||Faces||Schläfli symbol||Vertex configuration|
The three regular tessellations of the plane are closely related to the Platonic solids. Indeed, one can view the Platonic solids as regular tessellations of the sphere. This is done by projecting each solid onto a concentric sphere. The faces project onto regular spherical polygons which exactly cover the sphere. There are three possibilities:
|A vertex needs at least 3 faces, and an angle defect.
A 0° angle defect will fill the Euclidean plane with a regular tiling.
By Descartes’ theorem, the number of vertices is 720°/defect.
grundbogen til LOGOs TURTLE 🙂
Source: Turtle Geometry | The MIT Press
sudo apt-get update
sudo apt-get install linux-image-ev3dev-ev3
Connecting to the internet over bluetooth: (to save battery)
link at ev3-dev
Home Accessories. 15cm empaistic pattern paint roller. Game Accessories. Musical Instrument Accessories. Beauty, Health. Beauty, Health Accessories. Great for decoration machine. Rubber roller the best choice for DIY painter. | eBay!
Christina Z. Anderson gives us the “why and how” of the gum process, including making negatives.Share this:Click to email this to a friend (Opens in new window)Click to print (Opens in n…
DESTILLERET VAND: 21°C
Blanding A: Ammoniumjerncitrat
100 ml (50 ml) distilleret vand ~21 °C
20 g (10 g) Ferric ammonium citrate (green)
Blanding B: Blodludssalt, rødt
100 ml (50 ml) distilleret water ~21 °C
8 g (4 g) Potassium ferricyanide
til inspiration – det praktiske er ikke løst endnu
“No one but a vandal would print a landscape in red, or in cyanotype.” (Peter Henry Emerson: Naturalistic Photography for Students of the Art, London: Sampson Low, Marston, Searle and Rivington, 1889) Citation courtesy of Luminous Lint/Mike Ware.
I happen to agree with Mr. Emerson so I tone pretty much all of my cyanotypes. I have several posts about different toners and how they (generally) look, but this post will go over the basic process of toning and try to troubleshoot a few common problems.
Toning a cyanotype involves two basic steps: a bleach phase, and a toning phase. Every toner I know of contains some type of tannin in it: tannin chemically binds to the iron in the emulsion and changes the color. If I understand this process correctly, it produces a form of gallic acid – used in dyes and inks, especially medieval ones. I’ve read that gallic acid is normally corrosive, but I’ve never found this to be the case with toned cyanotypes.
If you’re concerned about the archival quality of your toned cyanotypes, Dr. Mike Ware (inventor of the ”New” cyanotype process) has said that his family photo albums contain what he’s pretty certain are toned cyanotypes – because they look very similar to other alternative processes it’s easy to confuse with Van Dyke prints or Kallitype prints. I’ve personally never had issues with mine – I’ll get back to you in some 20 years or so and see if that’s still the case.
Keep in mind that toners are funny things – you can mix and match things, you can vary the sequence of bleach and toner and get different results. I have a lot of good results with simply leaving the prints in the toner for long periods of time without bleaching at all. Take things one at a time – don’t try to tone or bleach multiple prints together. Experiment and have fun with it! Just remember that the key to a successful toned print is to wash well between steps.
1. Toning Preparations:
Before you start your toning, always:
- Age your prints at least 24 hours for the emulsion to harden.
- Pre-wet your prints in filtered water to allow the solutions to penetrate the paper fibers evenly.
- It’s a good idea to have multiple prints – toning is fickle, you never know what you’re going to get.
- Plan to leave the print face down for long periods of toning, or plan enough time to “babysit” the print – agitate it while face up in the toner.
2. The Bleach Phase:
Bleaching is a tricky thing. The purpose of bleaching is to help break down the iron a little so that the tannin in the toner can “grab on” easily. If your water is heavily chlorinated, you may not even need to bleach your prints.
How much you bleach really depends on how you coat, how much emulsion is on the paper, and what toner you’re using. If you bleach too far, you lose shadow density. If you bleach too little, your shadows will stay a stubborn blue shade while your highlights cooperate.
Bleach types: the most common form of bleach solution is Sodium Carbonate. That’s Washing Soda, usually found in your grocery store’s cleaner aisle, or at a photography chemical supply store. Don’t confuse this with Sodium Bicarbonate – baking soda – it won’t react the same way.
Other types of bleach that I’ve used are Ammonia and regular chlorine bleach. Ammonia stinks, horribly, and usually produces a browner image. Chlorinated bleach destroys paper fibers and is better left to your laundry.
My typical bleach solution is about 1-2 teaspoons of Sodium Carbonate combined with 1 Liter of water. If your print turns a bright purple the second you place it in the solution, it’s too strong. Play with the solution until you’re comfortable with the rate of bleaching. As you practice bleaching, you’ll notice that it’s a good idea to yank the print out a few seconds before you think it’s ready – the print will continue to bleach a bit while starting to rinse.
Always rinse the print well in running water between the bleach phase and the toning phase.
3. The Toning Phase:
All cyanotype toners are pretty much variations on a black/brown/purple theme. Certain toners are more efficient and stain less, while other toners produce a wider range of possible colors. Keep in mind that all toners will stain your paper base a little despite your best efforts. (please note that the following links lead to blog post about the toners, or examples of the toner shade.)
Tea toner: Most tea toners that I use are brewed for about 10 minutes in 25o mL of hot water, then added to a 1.5 Liter of room temperature filtered water. I use about 8-10 small tea bags, not a very accurate measurement! Every type of tea has a different quality or color to it – make sure that you use teas with tannin in them like black tea or green tea – white tea, red tea, and most herbal teas don’t have enough tannin to do anything to your print.
Green tea produces an eggplant/black shadow, and is so mild that it doesn’t stain the paper base too badly. If you’re toning a high key image, green tea will sometimes produce a really cool pink highlight. It has a tendency to split tone for me because of my double coat of emulsion.
Black tea will stain your paper the most, but it produces a lovely warm black/brown shade that’s nearly impossible to get anywhere else. I generally use a Lipton tea product for iced tea, but any black tea will work. If you want an easy split toner with warm highlights and blue shadows, black tea is the fastest way to get it.
Earl Grey tea: avoid this one – it has a lot of oils in it that can damage your print.
Tea toners work really well with a minimum of bleaching, but they do require a longer immersion for the iron to shift. I normally tone prints in tea for about 2 hours, but depending on the print, it’s taken up to 8 hours. Some people suggest that tea toners should be hot for a faster toner – in my experience that shaves about 30 minutes off the toning time, and stains the paper much worse. It’s a good idea to let the print sit in clean filtered water for about 10 minutes before the final rinse to help remove some of the excess tannin. All tea toners should be used freshly brewed – they lose potency after a day and should not be reused.
Tannic Acid Toner: This stuff is a royal pain to work with. It can produce the closest thing to a true black, but it’s far more likely to screw up, or produce a weird purply brown shade. It has the widest range of color tones that I’ve seen in a toner, but you have absolutely no control over what you get. Be extremely careful how much bleaching you do, because this toner is totally unforgiving if you go the slightest bit too far.
Done well, this toner produces the least paper staining – however, I’ve run into some chemical issues that I don’t quite understand that leave my paper the shade of cardboard. (I’ve narrowed it down to interactions with the tap water, or the age of the toner.)
Tannic Acid is produced from wood chips, and is extremely hard to mix into a solution. It’s a gummy mess. Because of this it’s difficult to estimate how much I use, but generally about a Tablespoon mixed into a Liter of water is a good place to start (and then remove the gummy bits.) A good tannic acid solution should be almost clear, and will take a minute of sitting in filtered water to fully tone out. Toning times for tannic acid are usually quite short.
If mixed with distilled water, tannic acid toner will last for a few weeks/months. A little mold is normal, just filter the solution every time you use it. Once the solution starts turning a dark brown or granulating (tiny little granules appear – not sure what they are) it’s time to start fresh. Tannic acid is also quite expensive, and only available at a photography chemical supply store like Photographer’s Formulary.
Coffea Toner: I love coffee toner. It’s a cold toner, as opposed to the warmer tea shades, and it leaves the paper pretty close to the original color. It will still stain, just not as badly as tea. Coffee doesn’t produce a true black, but more of a blue/black like a blackbird’s feathers. The highlights will stay pretty clean so make sure your contrast is good and your highlights aren’t blown out.
I generally use the cheapest instant coffee I can find – about 4-5 heaping tablespoons of instant coffee dissolved into 250 mL of hot water, then added to 1.5 Liters filtered room temperature water. I’ve read that other people have great success re-brewing used coffee grounds – since I don’t drink coffee I can’t exactly test this.
Coffee toner doesn’t seem to take quite as long as tea toner, but expect at least an hour of toning, perhaps more. Again, it’s a good idea to let the print rest in a water bath before the final rinse.
Wine Tannin: This is my new favorite toner, and I don’t have that much experience with it yet. So far, it produces a nice dark shadow and a brown/tan highlight on a fairly regular basis. It can be rather fickle if you keep the solution for a long period of time, so I suggest storing this toner no more than a month.
Wine tannin is basically the same thing as tannic acid, but produced from a different source. It’s designed to use in microbrewing so it mixes into solution a lot easier. It leaves the paper almost paper white, producing almost no staining. It’s slightly cheaper than tannic acid, but since it requires more to produce the same effect – half an ounce of wine tannin mixed into 1 L of water – the price is probably pretty close. I use the powdered version, but some stores have a liquid solution available.
Wine tannin has a tendency to put any coating discrepancies on display. Unless I use the Christopher James variation listed in the link (toss the print into the tannin instead of bleaching first) I lose some of my highlight detail. Like the tannic acid, it works pretty quickly. Wine tannin also has a weird chemical reaction that can turn my paper to a cardboard brown, requiring a water bath before the final rinse.
1. My print looks faded! What happened? You probably bleached the print too far. Try test strips in varying times to get a better idea of what works – the ideal is to tone your shadows dark without losing highlight details. Usually this means bleaching until the shadows are a dark purple and the highlights are slightly yellow.
2. I left the print in the toner forever, but it’s still blue! What now? Rinse the print for at least 5 minutes and go back to the bleach bath. After bleaching again – just a little, rinse it again for 5 minutes and put it back in the toner. Your initial bleach probably didn’t break the iron down enough.
3. The print toned nicely, but now that it’s dry I hate it! Why does it look so flat? I don’t know why, but that’s normal for a toned cyanotype. Try brushing a diluted solution of acrylic gloss medium onto the print to bring back the shadow depth and give the surface a little shine. It will look like it did when the print was wet.
4. Why can’t I produce the same results each time? What am I doing wrong? Nothing. That’s a quirk of toning. If you have a batch of prints that need to look similar, try toning them all at the same time with the same solution. Otherwise you run the risk of variations that you may or may not like. If you’re still having issues, stick with the basic tea toner – it’s a little less fickle.
5. My print looks mottled – it didn’t tone evenly. What’s going on? If you’re leaving the print in the toner for a long period of time, make sure you place it face down. Paper floats oddly, and you may end up with “dry” spots that don’t tone evenly. If you’re toning face up, make sure you agitate the print constantly.
6. My print has a bright blue round spot on it! Yup, the curse of the air bubble strikes again. Make sure the print is lying face down – ease the print into the toner slowly and work all the air bubbles out past the far edge. If you already have the blue spot on it, try a quick rinse, bleach bath, and return the print to the toner for a bit to remove the blue.
7. My shadows are blah. What happened to my perfect exposure? Your original shadows need to be a nice, deep, cobalt blue to tone dark. If your shade of cyanotype isn’t dark enough, it’s not going to tone well. Read this tutorial and do some experimenting with your paper and your developer first before you try toning again.
UK: Ferric ammonium citrate
DE: Ammoniumeisen (III)-citrat
C6H8O7 ·xFe3+ · yNH3
Synonym: Ammonium ferricitrat, ferri ammoniumcitrat.
Synonym: Kaliumhexacyanoferrat, rødt blodludsalt
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