Cyanotype vs Van Dyke Brown vs Salt Print
How cyanotype, Van Dyke brown and salt printing differ in chemistry, cost, fixing and paper, and which of the three a beginner should actually start with.
Three sunlight processes, three completely different shopping lists — and only one to start with.
The dividing line is silver, not colour
Group these three together and you get a reasonable-sounding story: three Victorian processes, three colours, one basic idea. Coat a sheet of paper, lay a negative on it, leave it in the sun. The story holds right up until you total the receipts, and then it falls apart — because two of these are silver processes and one is not, and almost every practical difference between them follows from that single fact.
Cyanotype uses two iron salts and no silver whatsoever. Van Dyke brown adds silver nitrate to an iron base. Salt printing is silver from end to end, and it is the only one of the three where the light-sensitive paper is something you manufacture yourself across two separate coating sessions. If you want the chemistry of the blue one on its own first, how a cyanotype actually works covers it in isolation. What follows is what changes when you step sideways into silver.
The short version
- Start with cyanotype, always: it is the only one of the three with no silver, no fixing bath, and no way to ruin the print after the exposure is finished.
- Van Dyke brown is the real second step: the same coat-and-sun workflow, but three chemicals instead of two, a fixing bath that has to be weak, and a wash that has to be long.
- Salt printing is the hardest of the three, not the middle one: you salt the paper in one session and sensitise it with silver in another, at two to three times the silver concentration Van Dyke uses.
- The shopping lists barely overlap: starter kits run roughly $25 for cyanotype, $59 for Van Dyke brown and $77 for salted paper, and the silver processes also demand paper that cyanotype will happily do without.
- Difficulty does not track exposure time: Van Dyke brown prints in a few minutes of strong sun and salt in 10 to 20, while forgiving, beginner-friendly cyanotype is the slowest of the three.
The three processes side by side
Kit prices are comparable ready-made starter kits from a single catalogue, so the ratios between them matter more than the exact figures.
| What you are comparing | Cyanotype | Van Dyke brown | Salt print |
|---|---|---|---|
| Chemicals in the sensitiser | Two, both iron | Three, iron plus silver | Two, coated in separate sessions |
| Silver content | None | About 4% | 10–12% |
| Fixing bath | None — plain water | Yes, heavily diluted hypo | Yes, plus wash either side |
| Typical strong-sun exposure | 10 minutes to an hour | Roughly 2–5 minutes | 10–20 minutes |
| Paper you can get away with | Almost anything, cheap pad paper included | Cotton, coated thin and even | Unbuffered or acidified, or it fogs brown |
| Starter kit price | About $25 | About $59 | About $77 |
| Where it gets difficult | Little to go wrong | Fixing and washing | Two coating passes, no contrast control |
Why cyanotype forgives you and the silver processes don't
A cyanotype is finished when you rinse it. Five to ten minutes in cold water until the water runs clear, and the print is permanent. There is no fixing bath, no clearing agent, and nothing you can get wrong once the paper comes out of the sun — the blue even keeps deepening on its own for a day or three as it oxidises. Underexpose one and you have lost a sheet of paper and twenty minutes.
Both silver processes hand you a second chance to destroy the print long after the exposure is over. A Van Dyke has to be fixed, and the fixer has to be weak: about four heaping teaspoons of sodium thiosulfate to a litre of water, or ordinary photographic fixer cut to a tenth of its working strength. Use fixer at normal strength and it bleaches the image you just made. Then the print has to be washed properly — five minutes of running water, a hypo-clearing bath, and a final wash closer to half an hour — because cotton rag paper holds fixer stubbornly, and what stays in the fibres stains the sheet months later.
That is the real difference in difficulty, and it is why experienced printers are so consistent about the order. All three processes look nearly identical while you are coating and exposing. They diverge in the sink.
What "salting your own paper" actually involves
Salt printing is the one where the paper is not a purchase but a step. You coat the sheet with a 2% salt solution — two grams of pure salt in 100 ml of distilled water — under ordinary room light, then let it dry for about half an hour. Salted paper at that stage is completely stable and keeps indefinitely, so making a batch is worth the afternoon.
The second coat is where it turns demanding. Under a red safelight you coat the same side with a 10–12% silver nitrate solution, dry it in darkness, and then use it. Not tomorrow. Sensitised salted paper fogs within a day or two even when stored in complete darkness, which catches out anyone who assumes photographic paper can be prepared in advance. Silver nitrate also stains skin on contact, and those stains take over a week to fade.
The negative is the other trap. Salt printing is a printing-out process — the image appears during the exposure rather than in a developer — and it offers no contrast control once the exposure is set. A negative that gives a good cyanotype prints flat and lifeless as a salt print, so the two are not interchangeable, and anyone moving across has a round of negative-making ahead of them.
What everyone repeats — and what's actually true
Myth: they are variations of one process, so the technique carries straight across.
Reality: the coating technique does not. Cyanotype is routinely brushed on with a generous hand, but Van Dyke wants a single thin, even coat from a hake brush — two coats is a common cause of splotchy prints. If the paper starts to curl, there is too much sensitiser on it.
Myth: buy acid-free archival paper, it is the safe choice.
Reality: "acid-free" usually means buffered with calcium carbonate, and that buffer is the problem. It prints cyanotypes a dull blue-grey and gives salt prints a brown fog. What you want is unbuffered cotton paper — or soak a buffered sheet for about 20 minutes in 5% citric acid or half-strength white vinegar, then rinse it.
Myth: the harder processes need longer in the sun.
Reality: it runs the other way. Van Dyke brown is the fastest of the three, often finished in two to five minutes of strong sun, and salt printing takes 10 to 20. Classic cyanotype, the easy one, is the slowest, running anywhere from 10 minutes to an hour.
Myth: you can sensitise a stack of salted paper and print from it all week.
Reality: salted paper keeps indefinitely, but once silver goes on it fogs within a day or two even in the dark. Coat only what you intend to expose in the same session.
If you are buying for the first time
- Buy the cyanotype chemistry first and print through the whole kit before ordering anything with silver in it. A beginner cyanotype setup costs roughly a third of the salt-printing equivalent, and the skills it teaches — even coating, judging exposure, holding contact pressure — are exactly the ones that transfer.
- Get a proper split-back contact printing frame rather than a clip frame. It holds the negative flat against the paper across the whole sheet and lets you inspect the exposure without losing registration.
- Order unbuffered cotton paper rather than paper sold as "acid-free". Papers made specifically for alt-process work are the trouble-free option; ordinary art paper usually needs an acid soak first.
- Buy sodium thiosulfate in bulk as pool dechlorinator instead of branded photographic fixer. It is the same compound, and both silver processes get through a lot of it.
- Make a test strip for every new combination of paper, light source and negative. Exposure times quoted by other people are a starting point and nothing more.
- Do not buy silver nitrate until you have somewhere dim to coat and dry paper. Both silver processes need safelight conditions; cyanotype only needs a room away from direct sun and UV or LED lamps.
When are you ready for the second process?
The honest signal is a boring one: you are ready when your cyanotypes have become boring. When you can coat a sheet without streaks, guess the exposure to within a couple of minutes, and get the same result twice from the same negative, the coating-and-contact-printing half of the work has stopped being a variable. That is the point at which adding a fixing bath teaches you something rather than simply adding a new way to fail.
Van Dyke brown is the sensible next move rather than salt printing: the exposure is shorter, the paper takes one coating pass instead of two, and there is no second sensitising session under a safelight to schedule around. A Van Dyke brown starter setup also reuses most of what you already own — brush, glass, frame and trays all carry over, and only the chemistry and the paper change.
Salt printing earns its place after that, as the process that puts you in direct contact with the 1830s. Beyond it sits gum bichromate, the usual fourth step, which trades sunlight chemistry for pigment, multiple registered coats and dichromate toxicity. That is a different kind of difficulty altogether, and a subject of its own.
Frequently asked questions
Can I use the same negative for all three processes?
No, and the gap is wide. Each process needs its own negative density: one that makes a good cyanotype prints flat and weak as a salt print, because salt printing needs far more contrast and gives you no way to adjust it afterwards. Digital negatives are normally corrected with a separate tone curve for each process.
Do I need a darkroom for any of these?
Not a full darkroom, but the silver processes need a genuinely dim room. Cyanotype can be coated in a dimly lit space away from direct sun and from UV or LED lamps. Van Dyke brown and salt printing both need to be coated and dried under something like a red safelight, because the sensitised paper fogs under ordinary room lighting.
Why did my print fade or stain weeks after I made it?
Almost always fixer left behind in the paper fibres. Both silver processes need a wash sequence rather than a rinse: several minutes of running water, a hypo-clearing bath, then a final wash of around half an hour. Cotton rag paper holds fixer tenaciously, and a short rinse will not shift it.
Is a UV lamp worth buying instead of using the sun?
It buys consistency rather than speed. Sunlight is free and actually gives salt prints noticeably more contrast than a UV box does, but its intensity shifts hour to hour and season to season. A UV unit lets you repeat an exposure exactly and print at night, which matters most once you start testing paper and negative combinations systematically.