How to make a digital negative
- Add your photo and set the size of the final print.
- Set contrast and midtones. The preview shows a cyanotype; the negative itself works for any contact process.
- Print the PDF on inkjet transparency film at 100%, and contact-print it with the ink side against your sensitised paper.
Processes and starting points
| Process | Negative it likes | Starting adjustment |
|---|---|---|
| Cyanotype | Long tonal range, dense highlights | Contrast +20 to +40 |
| Salt print | Very long range, high contrast | Contrast +40 to +60 |
| Van Dyke brown / kallitype | Long range | Contrast +20 to +40 |
| Platinum / palladium | Long range, smooth midtones | Contrast +20, midtones by test |
| Silver gelatin contact print | Normal range | No change |
These are only starting points: printer, film, ink and chemistry change the result. Always print the 21-step tablet with your first negatives and adjust until you see separation across the steps.
Tips for better negatives
- Use transparency film made for inkjet printers, rough (coated) side up in the printer.
- Choose the printer’s highest quality or photo setting; let the ink dry fully before exposing.
- Keep the negative clean and flat: press it under glass during exposure.
- Check the photo has enough pixels for the size with the print size calculator.
Frequently asked questions
Which processes can I use these negatives for?
Any process that is contact-printed under UV light or an enlarger: cyanotype, salt print, Van Dyke brown, kallitype, platinum/palladium, gum bichromate (one negative per layer) and silver gelatin contact prints.
Is this the same as a calibrated curve?
Not exactly. Professional workflows build a correction curve for each printer, film and process. Here you start with a straight inversion, print the 21-step tablet with your negative, and adjust contrast and midtones until the steps separate well on your prints.
Why black ink only?
A black-and-white negative printed with black ink is the simplest to control. Some printers give more UV density when the black is built from colours too; try your printer’s colour and greyscale settings with the step tablet to see which blocks more light.
What resolution is the PDF?
The negative is placed at 300 pixels per inch at its exact print size; print at 100% / “actual size”.
Are my photos uploaded?
No. Everything happens in your browser, so your photos never leave your device.
Last updated 2026-10-24.