Make a digital negative for cyanotype
Choose a photo and a print size and see the negative the Cyanotype app makes for contact printing: black and white, inverted, mirrored, cropped to the paper. This is an on-screen preview; the full-size print negative is made in the app. It runs in your browser and your photo is not uploaded.
Print size
Preview only, at most 600 px on its long side. Full-size print negatives at 4 × 5, 5 × 7 and 8 × 10 are made in the app.
Everything runs in your browser; your photo never leaves this device. No calibration curve is applied.
What a digital negative is
A photo can be printed as a cyanotype by putting a negative of it on the coated paper where you would put an object. Jacquard describes it:
“Use a digitally-printed photographic negative (an inverted black and white photo inkjet-printed onto a transparency*) instead of an object to create full-resolution photographs on paper or fabric.” [Jacquard, Cyanotype Chemistry]
What this tool does
- Crops to the paper. For 4 × 5, 5 × 7 and 8 × 10 the photo is cut from the center to the paper’s shape, keeping its own orientation: a landscape photo on 4 × 5 is cropped 5 × 4 wide. Square crops to a square. Free keeps the photo’s own shape.
- Makes it black and white, then inverts it, so light parts of the photo are dark on the film and block the sun, as a negative should.
- Mirrors it left to right. The app’s negative sheet tells you to lay the printed side against the coated paper. Mirrored this way, the print then reads the right way round.
- Adds nothing. No grain, no paper texture, no border and no calibration curve. Those belong to your chemistry and your printer.
- Shows it on screen only. The preview is at most 600 pixels on its long side and there is no file to save. The print-size negatives for 4 × 5, 5 × 7 and 8 × 10 paper, at the resolution that prints at the paper’s size, are made in the app.
The preview matches the negative the app makes. An automated test compiles the app’s own negative and crop code and requires this page to match it.
Making one by hand
You can do the same in any photo editor: make the photo black and white, invert it, flip it left to right, crop it to the paper, and print it on transparency film at 100%. The app does these steps for you and makes the negative at print size.
Printing it
The app’s sheet says to print the negative on transparency film at 100% and to adjust exposure to your chemistry. The film then goes on the coated paper, and Jacquard’s advice about the contact is:
“Using a film negative to make cyanotype prints is a contact printing process. The film must be flush on the print surface for optimal resolution and detail. Otherwise, the print may appear out of focus or blurry.” [Jacquard, Cyanotype Tips and Troubleshooting]
If the print comes out dark or blown out, Jacquard points at the film itself:
“The dark areas of the film may not be dense and opaque enough to block the light adequately.” [Jacquard, Cyanotype Tips and Troubleshooting]
“Stacking two negatives may be the best solution—this will double the opacity and contrast.” [Jacquard, Cyanotype Tips and Troubleshooting]
For how long to expose, see exposure time. For the whole process, how to make a cyanotype.
On your phone
The Cyanotype app makes the same negative on an iPhone or iPad. In the app it is under the share button, Digital negative; the sheet has Save to Photos and Share. The app makes the full-size negative this preview only shows, and also shows your photo as a cyanotype print first, in seven looks.
On your phone: Cyanotype
For iPhone and iPad.
The app shows your photo as a cyanotype print first, in seven looks, with print sizes and matte borders, so you can see the blue before you coat anything. Then it exports the digital negative at full resolution: black and white, inverted and mirrored, and for 4 × 5, 5 × 7 and 8 × 10 paper at the resolution that prints at the paper’s size. It all happens on the device. There is no account, and the app makes no network connections.
How this was checked
Statements about the process, its chemicals, safety and history are quoted word for word from the maker’s instructions (Jacquard), the Getty Museum and the Photographers’ Formulary safety data sheets, and linked where they appear (checked ). Where we could not fetch a source for a fact, we left the fact out, so this section gives no concentrations or amounts of chemicals: use the instructions and safety data sheet that come with what you buy. The digital negative tool is compared by an automated test with the Cyanotype app’s own code. If something here is wrong, tell us at a@noshu.net.