Free course · 5 steps · Several sessions over a few weeks
Beyond cyanotype: Van Dyke, salt and platinum
Make prints in three more historic processes, choosing paper and chemistry with care for the silver, gold and platinum salts they use.
For anyone who has completed "Make your first cyanotype". These processes use silver, gold or platinum salts, which cost more and need more care than cyanotype does.
What you need
- Smooth, well-sized cotton paper
- Silver nitrate, ferric ammonium citrate and tartaric acid, for Van Dyke
- Brushes or a glass rod, and a contact frame
- A UV light source or strong sunlight
- A negative the same size as the print, such as a digital negative
- Gloves and eye protection
Safety
Official hazard classifications for the chemicals this course uses. Read the chemicals pages for the details.
| Chemical | Hazards |
|---|---|
| Silver nitrateDanger | May intensify fire; oxidiser.; Causes severe skin burns and eye damage.; Very toxic to aquatic life with long lasting effects. |
| Gold(III) chlorideWarning | May cause respiratory irritation.; Causes skin irritation.; Causes serious eye irritation. |
| Ferric ammonium citrate (green or brown)Warning | Causes skin irritation.; Causes serious eye irritation. |
| Tartaric acid (L-)Danger | Causes serious eye damage. |
| Sodium chloride | Not classified as hazardous |
| Sodium thiosulfate pentahydrate | Not classified as hazardous |
| Ferric oxalateWarning | Harmful in contact with skin.; Harmful if swallowed. |
| Potassium chloroplatiniteDanger | Toxic if swallowed.; Causes skin irritation.; Causes serious eye damage.; May cause allergy or asthma symptoms or breathing difficulties if inhaled.; May cause an allergic skin reaction. |
| Sodium chloropalladiteDanger | May be corrosive to metals.; Harmful if swallowed.; Causes serious eye damage.; May cause an allergic skin reaction.; Very toxic to aquatic life with long lasting effects. |
| Potassium chlorateDanger | May cause fire or explosion; strong oxidiser.; Toxic if swallowed. |
| Potassium oxalate monohydrateWarning | Harmful in contact with skin.; Harmful if swallowed. |
| Ammonium thiocyanateWarning | Harmful if inhaled.; Harmful in contact with skin.; Harmful if swallowed.; Harmful to aquatic life with long lasting effects.; Contact with acids liberates very toxic gas. |
| Sodium carbonateWarning | Causes serious eye irritation. |
| Citric acidWarning | May cause respiratory irritation.; Causes serious eye irritation. |
| Sodium sulfite (anhydrous) | Not classified as hazardous |
Classifications from the European Chemicals Agency (official EU classification where one exists, otherwise the one agreed by REACH registrants or most often notified). Read the safety data sheet that comes with your chemicals, and dispose of them in line with local regulations.
Dispose of used chemistry according to the manufacturer's safety data sheet and your local council and water company rules.
Steps
1Choose your paper
Each process asks different things of paper, and a smooth, well-sized cotton paper suits several of them. For platinum and palladium, papers with alkaline buffers or optical brighteners are a problem.
Do this now
Filter the papers database for each process you plan to try and note the suitability ratings. Check the paper notes in the Van Dyke, salt and platinum guides before you buy.
Checkpoint: You have chosen a paper rated for the process you will try first.
2Compare the processes
Processes differ in difficulty, hazard, cost, permanence and the negative they need. Seeing them side by side shows what you are taking on before you buy chemicals.
Do this now
Sort the comparison by difficulty, hazard and cost, then open the rows for Van Dyke, salt printing and platinum and palladium. Note the negative density range, the equipment and the permanence for each.
Checkpoint: You can now compare the three processes by hazard, cost, permanence and the negative they need.
3Make a Van Dyke brown print
Van Dyke brown is an iron and silver printing-out process, so you can watch the image form. It has a reputation for permanence problems that comes from incomplete fixing, so fixing and toning matter.
Do this now
Read the safety table first, then work wearing gloves and eye protection, keeping silver nitrate away from combustible materials and out of the drain. Coat the paper under subdued tungsten light and dry it in darkness, expose by contact under UV, rinse, gold tone as the guide recommends, fix in a ventilated space for no longer than the guide says and wash thoroughly. The gold toner contains thiocyanate, which gives off a very toxic gas in contact with acids, so keep it away from acids.
Checkpoint: You can now make a Van Dyke brown print and explain why fixing and toning matter for its permanence.
4Make a salt print
Salt printing was the first paper-based photographic process, and like Van Dyke it prints out under UV. Untoned salt prints fade, so the guide strongly recommends gold toning, which must be done before fixing.
Do this now
Salt the paper and let it dry, then sensitise it with silver nitrate in subdued light and dry it in darkness. Expose until the shadows are darker than you want, wash, gold tone, and fix in two fresh baths in a ventilated space without prolonging the fixing. Wear gloves and eye protection throughout, as silver nitrate and gold chloride are both hazardous.
Checkpoint: You can now make a salt print, gold tone it before fixing, and wash it properly.
5Learn the platinum and palladium process
Platinum and palladium prints are among the most permanent photographs possible, and the metals are very expensive. Platinum salts can cause a permanent allergy, so palladium is the lower-risk choice, and gloves matter for both.
Do this now
Read the safety table and the platinum sensitisation warning before you buy anything, and choose a paper without alkaline buffers. Then follow the guide to coat, dry, expose under UV with a suitable negative, develop, clear and give a long final wash. Wear gloves and eye protection, work in a ventilated space when you mix the clearing baths, avoid dust, store potassium chlorate away from organic materials, acids and fuels because it is a strong oxidiser, keep the developer out of metal trays, and never use kitchen utensils.
Checkpoint: You can now describe the platinum and palladium process and handle its salts with the precautions it needs.