TBS-002 — Mini-TBS Shopping List¶
Complete itemized list for building the Mini-TBS classroom camera (two-box design) and making 20 cyanotype prints on watercolor paper. All quantities include 25% overage for waste and practice.
Target budget: $108–$175 (see summary at bottom).
1. Box and Construction¶
| Item | Qty | Supplier 1 | Price | Supplier 2 | Price | Notes |
|---|---|---|---|---|---|---|
| Medium moving box (18×18×16") | 2 | U-Haul | $4.50 ea | Home Depot | $3.98 ea | One camera box + one prep box |
| Black duct tape, 2" × 30 yd | 1 roll | Home Depot | $5.98 | Dollar Tree | $1.25 | Light sealing, hinges, sleeve attachment, and the panel hinge — one roll covers the entire build |
| Masking tape, 1" | 1 roll | Dollar Tree | $1.25 | Office Depot | $2.49 | Temporarily seals the prep-box top flaps for coating + exposure (peels cleanly) |
Subtotal: $10–$17
2. Pinhole Materials¶
| Item | Qty | Supplier 1 | Price | Supplier 2 | Price | Notes |
|---|---|---|---|---|---|---|
| Aluminum beverage can | 1 | — | Free | — | Free | Empty, clean, dry. Use flat side wall. |
| 1/32" (0.794mm) drill bit | 1 | Home Depot (Milwaukee) | $3.97 | Ace Hardware | $4.49 | HSS twist drill. Buy 2 in case of breakage. |
| Pin vise (hand drill chuck) | 1 | Home Depot | $5.97 | Amazon | $6.99 | Accepts 0–1/8" bits. Not a power drill. |
| 400-grit sandpaper, 1 sheet | 1 | Home Depot | $1.28 | Auto parts store | $1.50 | For prepping aluminum surface |
| 600-grit sandpaper, 1 sheet | 1 | Home Depot | $1.28 | Auto parts store | $1.50 | For deburring the drilled pinhole |
Subtotal: $8–$15
3. Chemistry¶
The Ware New Cyanotype formula — identical to the TBS-001 specification. See Chemistry Shopping List for full formula details and the Pinhole Optics Report for spectral and exposure properties.
Quantities Needed (20 prints + 25% overage)¶
| Chemical | Amount needed | Min order size | Notes |
|---|---|---|---|
| Ammonium iron(III) oxalate / ferric ammonium oxalate (Part A) | 30 g | 100 g | Covers many more prints (see the minimum-order table) |
| Potassium ferricyanide (Part B) | 8 g | 100 g | Covers many more prints (see the minimum-order table) |
| Ammonium dichromate | 1 g | 10 g | Optional — contrast enhancer; omit to save cost |
Suppliers and Pricing¶
| Chemical | Supplier 1 | Price | Supplier 2 | Price |
|---|---|---|---|---|
| Ammonium iron(III) oxalate (ferric ammonium oxalate), 100 g | Bostick & Sullivan | $18.00 | Photographers' Formulary | $24.50 |
| Potassium ferricyanide, 100 g | Bostick & Sullivan | $8.50 | Photographers' Formulary | $9.95 |
| Ammonium dichromate, 10 g | Photographers' Formulary | $12.00 | — | — |
Supplier URLs:
- Bostick & Sullivan: bostick-sullivan.com
- Photographers' Formulary: stores.photoformulary.com
Chemistry subtotal: $25–$45 (lower end omits ammonium dichromate)
Hazard note: Ammonium dichromate is a Category 1A carcinogen. Wear nitrile gloves when handling. For the classroom, it is safe to omit — prints will have slightly lower contrast but will still produce clear, presentable images.
4. Substrate¶
| Item | Qty | Supplier 1 | Price | Supplier 2 | Price | Notes |
|---|---|---|---|---|---|---|
| Watercolor paper, 10×14" block (20 sheets), hot-press, 140 lb (300 gsm) | 1–2 blocks (20–25 sheets) | Blick Art Materials (Arches Aquarelle) | $44.99/20-sheet block | Amazon (Fabriano Artistico) | ~$2.50/sheet | 100% cotton. Standard 10×14" size — one sheet per print, no cutting. |
Why watercolor paper? For the 10×14" prints it is the ideal substrate: it lies flat without stretching, coats evenly, and needs no pre-treatment. It is also cyanotype's traditional and most forgiving surface.
Yield: One 20-sheet block = 20 prints, used whole (no cutting). For the 25% practice/waste margin, add a second block or a 10×14" pad. Arches Aquarelle and Fabriano Artistico both ship the 10×14" size in blocks and pads.
Subtotal: $45–$65
5. Tools and Consumables¶
| Item | Qty | Supplier 1 | Price | Supplier 2 | Price | Notes |
|---|---|---|---|---|---|---|
| Foam brushes, 2" (10-pack) | 1 pack | Home Depot | $4.97 | Dollar Tree (3-pack) | $1.25 | Disposable. One per session. |
| Plastic mixing cups, 8 oz (10-pack) | 1 pack | Dollar Tree | $1.25 | Amazon | $3.99 | For mixing sensitizer |
| Push pins / map pins (100-pack) | 1 pack | Dollar Tree | $1.25 | Amazon | $2.49 | Mount the paper to the panel (reusable) |
| Binder clips, 1" (24-pack) | 1 pack | Office Depot | $2.49 | Dollar Tree | $1.25 | Hold the panel upright in the window |
| Nitrile gloves (box of 50) | 1 box | Home Depot | $7.98 | Amazon | $6.99 | Wear during coating and mixing |
| Digital kitchen scale (0.1 g) | 1 | Amazon | $9.99 | Walmart | $8.98 | For weighing chemicals. Most kitchens already have one. |
Subtotal: $9–$16 (less if you already own a kitchen scale and gloves)
6. Photo Trays¶
One developing tray for the wash baths (development, §13). Coating happens on the panel, so no tray is kept inside the camera.
| Item | Qty | Supplier 1 | Price | Supplier 2 | Price | Notes |
|---|---|---|---|---|---|---|
| Paterson 12×16" Developing Tray (PTP326) | 1 | B&H Photo | $10.95 | Adorama | $10.95 | For the wash baths — empty and refill between the three rinses. |
Alternative: any plastic tray or basin at least 11 × 15" — a dollar-store storage tub works fine for the wash.
Subtotal: $11
7. Arm Sleeves¶
| Item | Qty | Supplier 1 | Price | Supplier 2 | Price | Notes |
|---|---|---|---|---|---|---|
| Black cotton fabric (for arm sleeves) | 2 pcs | — | Free | Joann Fabrics | $3.99/yd | Cut sleeves from a black t-shirt (free) or buy 1/2 yard |
| Rubber bands (heavy duty) | 4 | — | Free | Office Depot | $1.99 | For sealing sleeves at wrists |
Subtotal: $0–$6
Alternative — glovebox sleeves (§9.6 of the PoC). Instead of the fabric-sleeve + rubber-band pair above, build sealed lab-style glove tubes. Integral gloves = no per-student nitrile, no wrist bands.
| Item | Qty | Supplier 1 | Price | Supplier 2 | Price | Notes |
|---|---|---|---|---|---|---|
| Black contractor bag (3-mil, opaque) | 1 | Home Depot | $0.50/bag | Amazon | $18/20-ct | Cut two arm tubes; must be black/opaque, not translucent |
| Extra-large rubber gloves | 1 pr | Grocery/drug store | $3.99 | Amazon | $6.99 | Taped to the inner tube end — these are the chemical PPE |
Alternative subtotal: $4–$7 (replaces the fabric-sleeve line, not additive)
Budget Summary¶
| Category | Low | High |
|---|---|---|
| Boxes + construction (×2) | $10 | $17 |
| Pinhole materials | $8 | $15 |
| Chemistry (without ammonium dichromate) | $25 | $35 |
| Chemistry (with ammonium dichromate) | $37 | $45 |
| Substrate (watercolor paper) | $45 | $65 |
| Tools + consumables | $9 | $16 |
| Wash tray (Paterson 12×16", ×1) | $11 | $11 |
| Arm sleeves | $0 | $6 |
| Total (without dichromate) | $108 | $165 |
| Total (with dichromate) | $120 | $175 |
What the Minimum Order Gets You¶
The chemistry suppliers sell minimum quantities far larger than one camera build requires. The minimum orders provide enough material for:
| Chemical | Min order | This build | Remaining | Additional prints |
|---|---|---|---|---|
| AmFe, 100 g | 100 g | 30 g | 70 g | ~45 more |
| K₃[Fe(CN)₆], 100 g | 100 g | 8 g | 92 g | ~230 more |
| Paper (10×14" blocks, ×2) | 40 sheets | 25 sheets | 15 sheets | ~15 more |
The leftover chemistry is enough for extended testing, workshops, or demonstrations.
Sourcing Notes¶
-
Boxes: You need two identical 18×18×16" corrugated boxes. Buy both from the same supplier for a perfect match. U-Haul, Home Depot, Lowe's, and Staples all carry equivalent sizes. The key specification is the 18" depth (which becomes the focal length).
-
Drill bit: The 1/32" size is stocked in the drill bit aisle at Home Depot, usually in a small-bits assortment pack. A single bit is ~$4. Buying a set of small bits ($8–12) gives you spares.
-
Chemistry lead time: Bostick & Sullivan and Photographers' Formulary ship within 1–3 business days to most US addresses. Plan 5–7 days from order to delivery.
-
Watercolor paper: Must be 100% cotton (rag), hot-press, 140 lb (300 gsm) minimum. Arches Aquarelle is the gold standard for cyanotype — widely available at Blick Art Materials and most art supply stores. No pre-treatment needed.
-
Substitutions:
- No pin vise? Use a sewing needle pushed through from behind (produces ~0.5mm hole — usable but slower exposure)
- No foam brushes? A natural-hair watercolor brush or small paint roller works
- No duct tape? Multiple layers of black electrical tape, though less durable
- No hot-press paper? Cold-press watercolor paper works but has visible texture in the print