Chemistry Shopping List — Cyanotype¶
Giant Pinhole Camera: Raw Material Procurement (chosen process)¶
Image plane per print: 4,499 × 2,388mm (~116 sq ft active film zone; container interior 5893 × 2,388mm)
Run size: 50 prints
Total substrate area: ~5,800 sq ft
Pricing basis: April 2026. Prices marked † are confirmed from supplier listings. All others are close estimates from current market data and should be verified before ordering. All prices USD unless noted.
Alternative processes¶
Cyanotype is the chosen process. For the cost of the alternatives considered (gum bichromate, Van Dyke Brown, salt, Ilford RC, Liquid Light), see Process Comparison.
Shared Item: Substrate Fabric¶
All iron/silver processes use unbleached cotton muslin as the substrate. 50 prints at ~116 sq ft each, plus 15% waste = ~6,670 sq ft total; at 60" (5 ft) wide fabric that is 6,670 ÷ 5 = ~1,334 linear feet ≈ 445 linear yards.
| Item | Qty | Supplier | Unit | Units needed | Unit price | Total |
|---|---|---|---|---|---|---|
| Unbleached cotton muslin, 60" wide | ~445 yd | Fabric Direct | 150-yd roll | 3 rolls | ~$100/roll | ~$300 |
| OR by the yard | ~445 yd | Fabric Wholesale Direct | per yard | 445 | ~$0.80–$1.20/yd | ~$360–$540 |
Fabric Direct — 150-yard rolls of 60" unbleached muslin, medium weight
URL: fabricdirect.com
Fabric Wholesale Direct — 60" wide unbleached cotton muslin, sold by the yard or bolt
URL: fabricwholesaledirect.com
Preparation required: Pre-wash all fabric twice in hot water, no detergent. This removes sizing (starch filler) that repels sensitizer. Dry fully before coating.
Process 1: Cyanotype¶
50-print total (Standard ½-Ware default): ~$1,653 · ~$33/print — the full Lean/Rich per-tier breakdown is in the shopping list below.
Cyanotype uses the Mike Ware New Cyanotype formula (1994) as the primary sensitizer. This replaces the traditional Herschel ferric ammonium citrate (FAC) formula with ammonium iron(III) oxalate (AmFe) and achieves 4–8× faster exposures (baseline ~30–45 min in full sun vs 2+ hours for traditional) with denser shadows and finer tonal gradation.
Source: Ware, M., Cyanotype: The History, Science and Art of Photographic Printing in Prussian Blue, Science Museum, 1999. Formula and technical notes: mikeware.co.uk/mikeware/New_Cyanotype_Process.html (free).
Chemistry quantities — Ware New Cyanotype formula¶
The sensitizer is Ware's AmFe : potassium ferricyanide (Part A / Part B) with an ammonium-dichromate contrast additive:
| Reagent | Role | Notes |
|---|---|---|
| Ammonium iron(III) oxalate (AmFe) | Part A | requires warm water (50–60°C) to dissolve |
| Potassium ferricyanide | Part B | mixed with AmFe at Ware's 3:1 ratio |
| Ammonium dichromate | Part B additive | contrast enhancer — carcinogen, handle with care (see below) |
| Distilled / DI water | solvent | tap water + DI filter adequate; warm for Part A |
The per-print masses are under trial — two wet-on-wet coats at a diluted Ware strength, concentration-tier dependent — so they are not yet pinned; see Sensitizer Trials. The per-tier order quantities and cost (Lean / Standard / Rich) are in the shopping list below.
⚠ Ammonium dichromate is a known carcinogen (Category 1A) and oxidizer. Quantities here are small (~10g per print, 1 kg for 50 prints). Wear nitrile gloves and mix in ventilated area. Store away from flammables. No hazmat shipping at this quantity (< 1 kg per shipment from Photographers' Formulary).
Shopping list — Ware New Cyanotype (primary)¶
Preliminary — quantities and costs are subject to the Sensitizer Trials; the Standard ½-Ware tier is the working default. Generated from the parts registry.
| Reagent | Supplier | Lean ⅓-Ware | Standard ½-Ware (default) | Rich full-Ware |
|---|---|---|---|---|
| Ammonium iron(III) oxalate (AmFe) | Photographers' Formulary | 13 kg / $780 | 19.5 kg / $1,170 | 39 kg / $2,340 |
| Potassium ferricyanide | Bostick & Sullivan | 4.3 kg / $104 | 6.5 kg / $158 | 13 kg / $316 |
| Ammonium dichromate | Photographers' Formulary | $25 | $25 | $25 |
| Chemistry subtotal | $909 | $1,353 | $2,681 | |
| Unbleached muslin (substrate) | Fabric Direct | $300 | $300 | $300 |
| Total (50 prints) | $1,209 | $1,653 | $2,981 | |
| Per print | $24 | $33 | $60 |
No fixer required. Development in plain cold water. No darkroom required for processing.
Traditional Herschel formula (alternative — if AmFe unavailable)¶
Slower (4–8× longer exposures), but simpler preparation — FAC dissolves at room temperature.
| Item | Supplier | URL | Unit size | Units | Unit price | Total |
|---|---|---|---|---|---|---|
| Ferric Ammonium Citrate, green, 1 lb | Photographers' Formulary | stores.photoformulary.com/ferric-ammonium-citrate-green | 454 g (1 lb) | 31 | ~$30† | ~$930 |
| Potassium Ferricyanide | Same as above | — | — | — | — | — |
Source References¶
- Mike Ware — The New Cyanotype Process — AmFe sensitizer formula, the 3:1 ratio, and dichromate contrast (also Ware, M., Cyanotype: The History, Science and Art of Photographic Printing in Prussian Blue, Science Museum, 1999).
- Muslin: Fabric Direct (150-yd rolls) · Fabric Wholesale Direct (by the yard).
- Reagents: Photographers' Formulary (AmFe, ammonium dichromate, FAC) · Bostick & Sullivan (potassium ferricyanide).
- Process Comparison — cost of the rejected alternative processes.