Process Comparison — Alternative Photographic Processes¶
Research / decision record. Cyanotype is the chosen process for TBS-001 — its procurement is in the Chemistry Shopping List. This document compares the cost of the alternative contact-printing processes that were considered and rejected, for the record. Run size 50 prints; substrate as in the shopping list. Prices are April-2026 estimates; verify before use.
Executive Cost Summary¶
| Process | Chemistry total | Substrate total | 50-print total | Per print |
|---|---|---|---|---|
| Cyanotype (Ware, lean) | ~$951 | ~$300 | ~$1,250 | ~$25 |
| Gum bichromate | ~$1,292 | ~$300 | ~$1,592 | ~$32 |
| Van Dyke Brown | ~$5,890 | ~$300 | ~$6,190 | ~$124 |
| Ilford RC paper | ~$1,141 (chemistry) | ~$13,500 (paper) | ~$14,641 | ~$293 |
| Liquid Light | ~$880 (chemistry) | ~$12,640 (emulsion+substrate) | ~$13,520 | ~$270 |
| Salt print | ~$16,472 | ~$300 | ~$16,772 | ~$335 |
Silver nitrate is the cost driver for salt print and Van Dyke Brown. Under the firm 2026 reagent prices (Artcraft Chemicals bulk: ferric ammonium oxalate $64/kg, potassium ferricyanide $51/kg), cyanotype is the cheapest process (~$1,250 lean) — below gum bichromate (~$1,592) and far below the silver-based processes. It is chosen on cost and on archival permanence, low hazard, and process simplicity (see Process 1).
Process 1: Cyanotype (the chosen process)¶
Cyanotype (Mike Ware's New Cyanotype) is the process TBS-001 uses; its full procurement, tiered recipe, and quantities live in the Chemistry Shopping List and Operating Manual. It appears here only as the cost baseline the rejected alternatives are measured against.
Cost basis: this document compares each process at its economical single-application formulation — for cyanotype that is the lean tier (~$25/print, ~$1,250 per 50-print batch) at the firm 2026 Artcraft bulk reagent prices. The project's as-built consumable budget instead uses Standard ½-Ware (~$34/print, ~$1,710 per 50-print batch), per the Cost Breakdown; the ~$25 here is cyanotype's floor, not a conflicting figure.
Why cyanotype: it is both the cheapest process and the one whose non-cost properties best fit a long-lived public artwork:
- Archival permanence. The Prussian-blue image is among the most lightfast and chemically stable of all iron-based prints — no silver to tarnish, no gum layer to crack or lift.
- Low hazard. Cyanotype's primary sensitizers (ferric ammonium oxalate + potassium ferricyanide) are far less hazardous than gum's bulk ammonium dichromate — a Category-1A carcinogen and Class-5.1 oxidizer used at 8.4 kg per run — or the DEA-controlled silver nitrate of the Van Dyke and salt processes. Cyanotype uses only a trace of dichromate as an optional contrast agent.
- Process simplicity. Development is in plain water: no toxic developer, stop, or fixer bath, no darkroom silver chemistry, and no multi-coat registration as gum requires for full density.
Process 2: Gum Bichromate¶
50-print total: ~$1,592 | Per print: ~$32
Chemistry quantities¶
| Reagent | Per print | × 50 prints | Order qty |
|---|---|---|---|
| Ammonium dichromate | 167 g | 8.4 kg | 9 kg |
| Gum arabic powder | 525 g | 26.3 kg | 27 kg |
| Dry watercolor pigment | 40 g | 2.0 kg | 2 kg |
Shopping list¶
| Item | Supplier | URL | Unit size | Units | Unit price | Total |
|---|---|---|---|---|---|---|
| Ammonium Dichromate, 1,000 g | Bostick & Sullivan | bostick-sullivan.com — ammonium dichromate | 1,000 g | 9 | $79.95 | ~$720 |
| Ammonium Dichromate (alt.) | Chem-Impex | chemimpex.com/products/37420 | 1 kg | 9 | ~$142.41† | ~$1,282 |
| Gum Arabic Powder, bulk | Gum Arabic USA | gumarabicusa.com/gum-arabic-bulk | Contact for 27 kg quote | — | ~$18–22/kg | ~$486–594 |
| Gum Arabic Powder (alt.) | Jedwards International | bulknaturaloils.com/acacia-gum-seyal-organic | Bulk kg | 27 | ~$20/kg | ~$540 |
| Dry pigment — raw umber or lamp black | Kremer Pigments | kremer-pigmente.com | 1 kg | 2 | ~$20–40/kg | ~$40–80 |
| Unbleached muslin | Fabric Direct | As above | 150-yd roll | 3 | ~$100 | ~$300 |
Process total: ~$1,592 (~$1,292 chemistry, ~$300 muslin)
Hazard: Ammonium dichromate is classified as an oxidizer (UN Class 5.1) and a known carcinogen (Category 1A, IARC). Must ship via UPS Ground only — no air freight. Wear nitrile gloves and N95 respirator when handling dry powder. Store away from flammables. The Photographers' Formulary listing explicitly states "Ground UPS only." Chem-Impex will require a completed hazmat shipping agreement.
Note: Gum bichromate at single coat per print. For multi-coat (4–8 coats for full density), multiply chemistry costs by 4–8. At 4 coats, total rises to ~$5,470 (~$5,170 chemistry + $300 muslin).
Process 3: Van Dyke Brown¶
50-print total: ~$6,190 | Per print: ~$124
Chemistry quantities¶
| Reagent | Per print | × 50 prints | Order qty |
|---|---|---|---|
| Silver nitrate (AgNO₃) | 41 g | 2.1 kg | 2.5 kg |
| Ferric ammonium citrate (green) | 106 g | 5.3 kg | 6 kg |
| Tartaric acid | 10 g | 500 g | 1 kg |
| Sodium thiosulfate (fixer) | 373 g | 18.65 kg | 25 kg |
Shopping list¶
| Item | Supplier | URL | Unit size | Units | Unit price | Total |
|---|---|---|---|---|---|---|
| Silver Nitrate, 1 lb (453 g) | Photographers' Formulary | stores.photoformulary.com/silver-nitrate | 453 g | 5 | ~$300–350 est. | ~$1,500–1,750 |
| Silver Nitrate, 100 g | B&H Photo | bhphotovideo.com — Photographers Formulary | 100 g | 21 | ~$110–130 est. | ~$2,310–2,730 |
| Silver Nitrate (bulk, lab grade) | Chem-Impex | chemimpex.com/products/00265 | 100 g / 500 g | Contact for 2.5 kg quote | ~$260/100g est. | ~$5,460 |
| Silver Nitrate (bulk) | Lab Alley | laballey.com/products/silver-nitrate-lab | Various | Contact for bulk | Market rate | Contact |
| Ferric Ammonium Citrate, 1 lb | Photographers' Formulary | As cyanotype above | 454 g | 12 | ~$30 | ~$360 |
| Tartaric Acid, 1 kg | Lab Alley | laballey.com/products/tartaric-acid-nf-fcc | 1 kg | 1 | ~$15–20 | ~$20 |
| Tartaric Acid (winemaking grade) | Enartis USA | shop-usa.enartis.com/tartaric-acid-food-grade-3 | Various | 1 kg adequate | ~$15 | ~$15 |
| Sodium Thiosulfate, 25 kg | Ingredient Depot | ingredientdepot.com/products/sodium-thiosulphate-25-kgs | 25 kg bag | 1 | ~$40–55 | ~$50 |
| Unbleached muslin | Fabric Direct | As above | 150-yd roll | 3 | ~$100 | ~$300 |
Process total: ~$6,190 (chemistry $5,890 + $300 muslin); silver nitrate cost varies ±20–30% by source — see procurement note
Critical procurement note — silver nitrate: - Silver nitrate is a DEA List I Chemical. US purchases require a DEA Form 224 registration for quantities above threshold (typically >400g). Photographers' Formulary explicitly states "DEA Form Required" on their listing. - Silver price is volatile. AgNO₃ is ~68% silver by weight; the silver market price directly affects the cost. Verify current pricing before ordering — it can shift 20–30% within weeks. - Silver nitrate permanently and irreversibly stains skin, clothing, and surfaces black. Nitrile gloves, lab coat, and eye protection mandatory for all handling. - Ships UPS Ground only (UN hazmat). No air freight.
Process 4: Salt Print¶
50-print total: ~$16,772 | Per print: ~$335
Chemistry quantities¶
| Reagent | Per print | × 50 prints | Order qty | Notes |
|---|---|---|---|---|
| Silver nitrate (AgNO₃) | 126 g | 6.3 kg | 7 kg | DEA form required; see above |
| Sodium chloride | 15 g | 750 g | 1 kg | Table salt adequate |
| Sodium thiosulfate | 746 g | 37.3 kg | 50 kg | Cheap bulk chemical; 25 kg bag × 2 |
Shopping list¶
| Item | Supplier | URL | Unit | Units | Unit price | Total |
|---|---|---|---|---|---|---|
| Silver Nitrate — contact for 6.3 kg quote | Ames Goldsmith | amesgoldsmith.com/products-services/silver-nitrate | Custom bulk | — | Market rate | Contact for quote |
| Silver Nitrate 1 lb | Photographers' Formulary | As above | 453 g | 14 | ~$300–350 | ~$4,200–4,900 |
| Sodium Chloride | Grocery / bulk food store | — | 1 kg | 1 | ~$2 | ~$2 |
| Sodium Thiosulfate, 25 kg × 2 | Ingredient Depot | ingredientdepot.com — sodium thiosulphate | 25 kg bag | 2 | ~$40–55 | ~$90 |
| Sodium Thiosulfate (alternative) | Alliance Chemical | alliancechemical.com/products/sodium-thiosulfate | 25 lb | 4+ | ~$35 per 25 lb | ~$140 |
| Unbleached muslin | Fabric Direct | As above | 150-yd roll | 3 | ~$100 | ~$300 |
The silver nitrate cost at 6.3 kg dominates entirely. At $260/100g, this is $16,380 in AgNO₃ alone. Salt print is included here for completeness but is not recommended for a 50-print run at this scale. Van Dyke Brown delivers a comparable aesthetic at roughly one-third the silver consumption.
Process 5: Ilford Multigrade RC Paper¶
50-print total: ~$14,641 | Per print: ~$293
Material quantities¶
| Item | Per print | × 50 prints | Order qty |
|---|---|---|---|
| Ilford MGRC 50"×98' roll | 0.33 roll (3 prints/roll) | 17 rolls | 18 rolls |
| Kodak Dektol developer (working) | 11.1 L | 555 L | 10 × 5-gal packets |
| Ilford Rapid Fixer concentrate | 3.0 L (makes 15 L working) | 150 L concentrate | 30 × 5L bottles |
Shopping list¶
| Item | Supplier | URL | Unit | Units | Unit price | Total |
|---|---|---|---|---|---|---|
| Ilford MGRC Pearl, 50"×98' roll | B&H Photo | bhphotovideo.com — ILMG50981P | 50"×98' roll | 18 | ~$700–800 est. | ~$12,600–14,400 |
| Kodak Dektol, 5-gal powder | B&H Photo | bhphotovideo.com — Kodak Dektol | Makes 5 gal stock | 10 | ~$28–35 | ~$300 |
| Kodak Dektol, 5-gal (alt.) | Adorama | adorama.com/kkdekpd.html | Makes 1 gal stock | 49 | ~$10–14 | ~$490–686 |
| Ilford Rapid Fixer 5L | B&H Photo | bhphotovideo.com — Ilford Rapid Fixer | 5 L concentrate | 30 | ~$18–22 | ~$540–660 |
| Ilford Ilfostop (stop bath) 1L | B&H Photo | bhphotovideo.com | 1 L | 7 | ~$10 | ~$70 |
Notes on paper rolls: - Ilford MGRC 50"×98' confirmed listed at B&H Photo (product #ILMG50981P). Price is not shown publicly — call B&H at 800-606-6969 or log in for current pricing. - 50" width × 98' length yields 4 strips of 50" × 84" per print (4 × 1,270mm = 5,080mm covers the 4,389mm active width with 691mm spare; each strip height = 2,094mm = 82.4"). 14 strips per roll ÷ 4 strips per print = 3 prints per roll (2 strips spare). - Paper must be cut and handled in sfaelight conditions.
Process 6: Rockland Liquid Light on Custom Substrate¶
50-print total: ~$13,520 | Per print: ~$270
Material quantities¶
| Item | Per print | × 50 prints | Order qty |
|---|---|---|---|
| Rockland Liquid Light | 141 oz (double coat) | 7,050 oz | 221 × 32oz OR contact Rockland for bulk |
| Developer (Dektol) | 11.1 L | 555 L | As above |
| Fixer | 15 L working | 750 L | As above |
| Substrate (muslin) | ~101 sq ft | ~5,050 sq ft | ~400 yd of 60" muslin |
Shopping list¶
| Item | Supplier | URL | Unit | Units | Unit price | Total |
|---|---|---|---|---|---|---|
| Rockland Liquid Light 32 oz | Adorama | adorama.com/chll32.html | 32 oz | 221 | ~$50–60 | ~$11,050–13,260 |
| Rockland Liquid Light 32 oz | B&H Photo | bhphotovideo.com — Rockland LLE8 | 8 oz | 882 | ~$25 | ~$22,050 |
| Rockland direct (bulk quote) | Rockland Colloid | rockaloid.com | Custom bulk | Contact | — | Recommended for 50-print volume |
| Developer, Fixer | As Ilford section | — | — | — | — | ~$880 |
| Muslin substrate | Fabric Direct | As above | 150-yd roll | 3 | ~$100 | ~$300 |
Procurement note: At 7,050 oz (~208 liters / ~55 US gallons), this volume of Liquid Light has no listed retail path that is commercially sane — 221 bottles at $55 each. Contact Rockland Colloid directly (rockaloid.com) before purchasing. Rockland does offer bulk supply to institutions and studios; the per-oz price drops significantly at this volume. A phone or email enquiry before ordering is essential for this process.
Shared Chemistry: Developer and Fixer (Silver Processes)¶
Applies to Ilford RC paper and Liquid Light. Both use standard silver gelatin processing chemistry.
Dektol developer — 555 L working solution total¶
| Item | Supplier | URL | Unit | Units | Unit price | Total |
|---|---|---|---|---|---|---|
| Kodak Dektol, 5-gal powder | Amazon | amazon.com — Kodak Dektol 5 gal | Makes 5 gal (18.9 L) stock | 10 | ~$28 | ~$280 |
| Kodak Dektol, 1-gal powder | B&H | As above | Makes 1 gal (3.78 L) stock | 49 | ~$12 | ~$588 |
At 1:2 dilution: 1 gallon stock → 3 gallons working. 5-gal packet → 15 gal (56.7 L) working. 10 packets × 56.7 L = 567 L working. Sufficient.
Fixer — 750 L working solution total¶
| Item | Supplier | URL | Unit | Units | Unit price | Total |
|---|---|---|---|---|---|---|
| Ilford Rapid Fixer, 5 L | B&H Photo | bhphotovideo.com — Ilford Rapid Fixer | 5 L concentrate | 30 | ~$20 | ~$600 |
At 1:4 dilution: 5 L concentrate → 25 L working. 30 bottles × 25 L = 750 L working. Exact.
Comparative Summary Table — 50 Prints¶
| Process | AmFe / FAC | KFe | AgNO₃ | Amm. dichromate | Gum arabic | Na thiosulfate | Fabric/paper | Chemistry | Total |
|---|---|---|---|---|---|---|---|---|---|
| Cyanotype (Ware, lean) | 11.4 kg AmFe | 3.8 kg | — | 0.4 kg | — | — | ~399 yd muslin | ~$951 | ~$1,250 |
| Gum bichromate | — | — | — | 8.4 kg | 26.3 kg | — | ~399 yd muslin | ~$1,292 | ~$1,592 |
| Van Dyke Brown | 5.3 kg FAC | — | 2.1 kg | — | — | 18.65 kg | ~399 yd muslin | ~$5,890 | ~$6,190 |
| Salt print | — | — | 6.3 kg | — | — | 37.3 kg | ~399 yd muslin | ~$16,472 | ~$16,772 |
| Ilford RC paper | — | — | — | — | — | — | 18 rolls paper | ~$1,141 (chem) | ~$14,641 |
| Liquid Light | — | — | — | — | — | — | ~399 yd + emulsion | ~$880 (chem) | ~$13,520 |
Key Procurement Notes¶
1. Silver nitrate — DEA registration required¶
Any US purchase of silver nitrate above certain thresholds requires completion of a DEA Form 224 (New Application for Registration). Silver nitrate is listed as a DEA List I Chemical due to its use in methamphetamine precursor chemistry. Photographers' Formulary states this explicitly on their product page. Allow 2–4 weeks for DEA registration approval before ordering. Form available at dea.gov.
2. Ammonium dichromate — hazmat shipping¶
Ammonium dichromate is a UN Class 5.1 oxidizer. Cannot be shipped by air. UPS Ground only within the continental US. Both Photographers' Formulary and Chem-Impex state ground-only shipping at checkout. It is also a Category 1A human carcinogen. Proper storage away from flammables is required; the material is capable of self-sustaining decomposition if ignited.
3. Silver nitrate price volatility¶
Silver nitrate is 63–68% silver by weight. The silver spot price (approximately $30–35/troy oz as of early 2026) directly sets the floor for AgNO₃ cost. A 20% increase in silver price increases salt print chemistry cost by approximately $4,430 on a 50-print run. Lock in pricing before committing to this process.
4. Liquid Light — contact Rockland before ordering retail¶
At the volume required for 50 prints (7,050 oz / ~208 liters), retail ordering is impractical. Rockland Colloid's website (rockaloid.com) is the primary source. Email or call before ordering — they have supplied institutions with bulk quantities before. The per-oz price at volume is lower than the retail 8-oz and 32-oz bottle pricing.
5. Cyanotype AmFe — preparation notes¶
Ferric ammonium oxalate (AmFe) requires warm water (50–60°C) to dissolve fully. Prepare Part A by adding AmFe to warm water and stirring until completely clear — a pale green-yellow solution. Do not use boiling water. Allow to cool before mixing with Part B. AmFe has a shelf life of 6–12 months in a sealed dark bottle at room temperature. If the traditional FAC formula is substituted: use only the green grade of ferric ammonium citrate (Fe³⁺, light-sensitive) — the brown grade (Fe²⁺) is not light-sensitive for cyanotype.
6. Muslin pre-treatment¶
Regardless of process, all muslin must be pre-washed twice to remove commercial sizing. Sizing is a starch/synthetic compound applied by fabric mills that repels water-based sensitizers. If not removed, the sensitizer will bead off the fabric rather than absorbing. Test a small piece before processing the full batch.
7. Bulk muslin ordering — consider width carefully¶
The muslin is cut to fit the washable tray area at 4,249 × 2,000mm (14'4" × 6'7") — slightly smaller than the 4,389 × 2,094mm film plane (the tray, not the optics, sets the size). Its 6'7" (2,000mm) height exceeds 60" (1,524mm) roll fabric, so widths must be joined in the height direction. At 60" wide, strips are cut 60"×172" and joined two-deep (2 × 60" = 120" covers the 79" height) — one horizontal seam per print. Alternatively, buy 120" (10ft) wide muslin from theatrical/backdrop suppliers and cut a single panel per print: the 120" width spans the 6'7" (79") height and a 14'4" length spans the width — one seamless panel.
Supplier Directory¶
| Supplier | Speciality | URL |
|---|---|---|
| Photographers' Formulary | Full range of darkroom and alternative process chemicals | stores.photoformulary.com |
| Bostick & Sullivan | Cyanotype, platinum/palladium, VDB, salt chemistry | bostick-sullivan.com |
| Chem-Impex | Reagent and lab-grade bulk chemicals incl. AgNO₃, dichromate | chemimpex.com |
| Lab Alley | Lab-grade chemicals, tartaric acid, silver nitrate | laballey.com |
| Ingredient Depot | Bulk food/industrial chemicals incl. sodium thiosulfate 25 kg | ingredientdepot.com |
| Alliance Chemical | Sodium thiosulfate and industrial chemicals, same-day ship | alliancechemical.com |
| Ames Goldsmith | Photographic-grade silver nitrate, bulk supply | amesgoldsmith.com |
| Gum Arabic USA | Bulk gum arabic in kg and larger quantities | gumarabicusa.com |
| Jedwards International | Bulk acacia gum / gum arabic wholesale | bulknaturaloils.com |
| Fabric Direct | 60" muslin in 150-yard rolls | fabricdirect.com |
| Fabric Wholesale Direct | 60" muslin by the yard or bolt | fabricwholesaledirect.com |
| B&H Photo Video | Ilford paper rolls, Rockland Liquid Light, Dektol, Ilford fixer | bhphotovideo.com |
| Adorama | Ilford paper rolls, Rockland Liquid Light, Dektol | adorama.com |
| Rockland Colloid | Liquid Light emulsion — contact for bulk pricing | rockaloid.com |
| Freestyle Photo | Alternative process chemicals, Arista developer | freestylephoto.biz |
See Also¶
- Chemistry Shopping List — procurement for cyanotype, the chosen process.
- Photosensitive Plane Options — the process-selection analysis that chose cyanotype.
- Operating Manual — cyanotype recipe tiers and chemistry preparation.
- Cost Breakdown — the project's as-built cyanotype consumable budget (Standard ½-Ware).
Per-item supplier links are inline in each process section and consolidated in the Supplier Directory above.