DIGITAL NEGATIVE
MATERIALS LIST
This is an ongoing list of suggested materials, products, and ideas, that I will continue to update. This is for reference and not everything is required for a workshop. I have tried to include products for varying levels and budgets. Consider your own goals, workflow, and space. Please share anything useful you come across that you think I should add.
TRANSPARENCY MATERIALS
Basic Digital Negative Generator:
Digital Negative Transparency Materials
The "Waterproof Positive Film for Silk Screen" product is not noticeably different from the one sold for alternative processes and works well for digital negatives. Neither is not functionally waterproof - but the ink does not run.
Pictorico Pro Ultra Premium OHP Transparency Film
Highest quality transparency. It has a slightly denser emulsion which could produce slightly longer exposure times.
*Buy the transparency/clear product not their “white film”
There have been stocking issues lately so stock up if you are working on a cohesive project.
Fixxons vs. Pictorico analysis https://www.youtube.com/watch?v=7fzAOhTls_o
Do new exposure tests when changing brands!
BOOKS LIST
Additional Articles and Resources
Contemporary Practices in Alternative Process Photography book series
The Book of Alternative Photographic Processes
By Christopher James
The cyanotype chapter is available to download: https://christopherjames-studio.com/sample-chapters
Mike Ware free technical articles:
http://www.mikeware.co.uk/mikeware/New_Cyanotype_Process.html
Alternative Process “cheat sheets”
https://www.alternativeprocesses.org/ap-cheat-sheets
CHEMICAL SUPPLIERS
Please let me know of any reliable international photo chemical suppliers I have not listed!
Dilution calculator:
https://www.alternativephotography.com/calculator-dilute-a-dilution/
INKJET PRINTERS
Here is an article comparing several printers for printing digital negatives.
https://toptenreviewed.com/best-printers-for-digital-negatives/
Canon Pro 1000 vs. Epson P900 (according to the internet)
Canon Pro 1000
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Has suction paper feed (reduces pizza wheel scratches on negatives).
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Canon has replaceable print heads so if one gets clogged it is an easier fix.
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Ink may be less expensive.
Epson P900
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Quadtone Rip (a complicated system for making digital negative curves) may only work on Epson printers.
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Has smaller dots and a “much higher printing resolution”
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More prone to clogging if not used regularly (that may be less of an issue with newer models).
Trouble Shooting:
Every printer will have its own quirks and issues when it comes to printing digital negatives.
Head strike - If the print head collides with the paper it can leave a big ink mark. This is most common on the edge of the paper but can happen anywhere, especially with curled paper or transparency.
-Try increasing the “platen gap” - instructions for this will be printer specific.
Epson: File > Print > Print Settings > Advanced Media Control
Banding - horizontal stripes in the print, as if a line of printing was skipped.
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First, try printing a nozzle check pattern on a piece of clean scrap paper in order to see if any inks are clogged.
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Turn off “high speed”
EXPOSURE
Sunlight Exposure
Here is a list of other artists' cyanotype exposure times all over the world at different times of the year.
www.alternativephotography.com/the-big-cyanotype-exposure-survey-results/
Many weather apps provide live UV Index ratings. The scale can be small without much precision but it gives you a framework.
Artificial UV Lights
Exposure lights for homemade boxes/setups must be UV lights.The wavelength is important; the best range for alternative processes is around 365 nm to 395 nm, and efficiency drops as it gets closer to 400 nm. 365 nm lights will be faster but are generally more expensive.
More information on UV wavelengths:
www.waveformlighting.com/tech/what-is-the-difference-between-365-nm-and-395
UV lights and UV boxes designed for screen printing work well. Some have lights on the bottom, and the print is placed face-down on glass. This system does not work for photograms of 3D objects. You want to ensure the light evenly exposes the full area of the largest print you intend to make.
Below are lights that will need a box or curtain of some sort.
Exposure Units
Metal boxes are often used (not required) because they become a heat-sink for the lights which can get hot. An exposure unit box or casing can be made out of something as simple as a black plastic tote/bin. The lights can be attached to the lid or flip it over and connect the lights to the bottom. As little as 4 in from lights to paper - this may take some trial and error depending on the lights.
Building a UV exposure box articles:
This is what I used for my homemade exposure unit:
Super Bright 60 Watts UV Black Light LED Strip (maybe with another set of similar lights?)
Cyanotype exposures are 40+ mins
9 inches from lights to contact frame glass (this could be a lot closer, which could make it faster)
To make this box I laser-cut the sides of the box and connected them with Unistrut. I had extra help spicing and reconnecting the LED strips to get them to lay flat like this. The Barrina lights would be easier to connect.
I plugged the lights into a standard darkroom timer.
UV Boxes
DIY UV Box Ideas
UV lights can get hot so be aware when using a plastic or flammable carrier.It is also dangerous to look at or be exposed to UV light, so it is good to have a protective box or curtain around the light when it is on. It can be helpful to run a light through a darkroom timer or smart plug in order to control exposure times.
Integrating Light Meter
One alternative to a UV light or exposure unit is a meter that measures accumulated UV light as opposed to the amount in a single moment. This makes measuring sunlight exposure very easy and consistent. The problem is that there is currently no perfect product.
Lightmeasure used to make one but they are no longer selling their devices.
A possible option (I have not tried) - shipping from Switzerland
*requires a power source - no batteries
https://www.ianleake.com/collections/light-counter-system?page=1
“While I use my devices for platinum printing, I have many customers using them to control exposures for cyanotype, gum, carbon, and even silver gelatin prints; both darkroom exposures and sun printing. Unfortunately, right now I have a component supply problem, so have none in stock. I hope to resolve this in a couple of months.” - 9/23/2023
“The basic system is a UV sensor (59 CHF) and a light integrator (339 CHF). About half my customers also buy a power controller, because this allows the light integrator to switch your light source on and off (depending on the light source for compatibility).”
If you or someone you know is very technically minded you could build one…
https://apenasimagens.com/en/solar-uv-exposure-meter-complete-project/
https://www.youtube.com/watch?v=42rwjuU4VrQ