Shipping, Packaging & Fulfillment Protocol

Operational Standard: Revision 2026.10

This document governs the physical packaging, reference card manufacturing, mailer box sizing, and quality fulfillment protocols for all StackCalc math manipulatives and hardware devices shipped from our California studio.

1. The $135\,\text{mm} \times 90\,\text{mm}$ Golden Reference Card Standard

Every physical StackCalc product kit includes a custom duplex Archival Reference & Video QR Card. The card acts as a protective cover over the nested Gridfinity tray and provides the customer with an immediate visual schematic and instructional entry point upon lifting the box lid.

SIDE A: FRONT (TOP-FACING)

Exploded CAD Isometric: Shows component orientation and tolerance alignment.
Content-Addressed SHA Manifest: Precise Git commit hashes for every part.
Anti-Arbitrage Pricing: 50% premium replacement model ($1.5\times$ amortized cost).
QC Stamp & Postal Notice: [ QC-CALIF-01 PASSED ] + USPS Pub 52 exemption.

SIDE B: BACK (VIDEO PORTAL & LESSON)

High-Contrast Vector QR Code: Deep links directly to product video suite.
3-Step Quick Start Lesson: Zero-to-concept hands-on math under 60 seconds.
Curriculum Standards: Explicit CCSS & Texas TEKS alignments.
District PO Channel: quotes@stackcalc.io for direct school orders.

Dimensional Engineering & Fit Rationale

Dimension	Specification	Engineering Justification
Width	$135.0\,\text{mm}$	Fits within $150\,\text{mm} \times 150\,\text{mm}$ laser engraving working beds with $7.5\,\text{mm}$ perimeter clamping margin.
Height	$90.0\,\text{mm}$	Fits inside standard $6 \times 4 \times 2\text{ in}$ ($152 \times 102\,\text{mm}$) corrugated mailers with $8.5\,\text{mm}$ finger extraction clearance.
Corner Radius	$r = 3.0\,\text{mm}$	Eliminates dog-earing, paper cuts, and friction snags inside corrugated boxes.
Aspect Ratio	$1.50 : 1$ ($3 : 2$)	Golden ratio matching standard photographic index plates and postcard standards.
Gridfinity Overlap	Spans 3x1 ($125.5\,\text{mm}$) and 3x2 ($125.5 \times 84\,\text{mm}$)	Sits flush on top of organizer bins as an integrated dust shield and presentation layer.

2. Production Substrates: Paper Printing vs. Laser Engraving

To balance volume fulfillment speed against premium unboxing aesthetics, StackCalc utilizes two validated manufacturing pathways:

flowchart TD
    Card["Archival Reference Card<br>135mm x 90mm (r = 3.0mm)"] --> Choice{"Production Pathway"}

    Choice -->|"Bulk School Districts (10-30 kits)"| Paper["Pathway A: High-Speed Office Laser"]
    Choice -->|"Retail, Keynote & SC-32 Hardware"| Laser["Pathway B: Precision Laser Engraved"]

    Paper --> P1["80 lb / 216 gsm Archival White Cardstock"]
    Paper --> P2["Clean White Background + Midnight Charcoal Text"]
    Paper --> P3["Pre-Cut 4x6' or 3.5x5' Manual Feed Tray"]
    Paper --> P4["Zero Manual Cutting • 30 Cards / Minute"]

    Laser --> L1["300 gsm Black Core Cardstock or Acrylic"]
    Laser --> L2["Strictly Monochrome White on Black (#FFFFFF)"]
    Laser --> L3["Vector Engrave + Vector Cut in 1 Single Pass"]
    Laser --> L4["Zero Manual Trimming • Ultra-Durable Classroom Life"]

Pathway A: High-Speed Laser Printer Paper (Bulk School District Orders)

Target Orders: Classroom 10-packs, 30-packs, and school district purchase orders.
Substrate: 80 lb / 216 gsm bright white acid-free cardstock.
Toner Strategy: Clean white background (#FFFFFF) with high-contrast midnight charcoal typography (#0F172A).
Why avoid full black flood? Flooding paper with black toner causes thermal curl, ink flaking on folds, and smudge risk during humid classroom use.
Zero-Cut Feeding Solution: Feed pre-cut $4 \times 6\text{ in}$ ($101.6 \times 152.4\,\text{mm}$) or $3.5 \times 5\text{ in}$ ($88.9 \times 127\,\text{mm}$) blank index cardstock into the laser printer's manual bypass tray, completely eliminating manual scissors or paper trimmer labor.
Throughput: ~30 double-sided cards per minute.

Pathway B: Precision Laser-Engraved Black Card (SC-32 & Retail Kits)

Target Orders: SC-32 scientific calculator, keynote showcase editions, and direct retail.
Substrate: 300 gsm black matte cardstock (with white core) or $1.0\,\text{mm}$ black anodized aluminum / black cast acrylic.
Color Constraint: Strictly Monochrome White on Black (#FFFFFF on #000000). Laser ablation vaporizes the black top coat to reveal crisp white substrate underneath.
Single-Pass Automation (Zero Manual Cutting):
The laser engraves the exploded wireframe, Part ID manifest, California QC badge, and Side B vector QR code.
In the same job without moving the substrate, the laser vector-cuts the outer $135.0 \times 90.0\,\text{mm}$ boundary with $r = 3.0\,\text{mm}$ rounded corners.
Finished, deburred cards drop out ready for packaging—zero manual labor.
Throughput: ~90 seconds per double-sided card.

3. Master Packaging Profiles & Box Dimensions

StackCalc standardizes on crush-proof corrugated shipping mailers that maximize physical protection and postal weight efficiency:

Profile	Dimensions (Exterior)	Dimensions (Interior)	Reference Card Position	Compatible Products	Postal Class
Box Tier 1	$7 \times 5 \times 2\text{ in}$ ($178 \times 127 \times 51\,\text{mm}$)	$6.5 \times 4.5 \times 1.9\text{ in}$ ($165 \times 114 \times 48\,\text{mm}$)	Rests flat on top of 3x1 Gridfinity bin	Algebra Boxes, Ten-Frames, Dice & Spinner	USPS Ground Advantage (<8 oz)
Box Tier 2	$8 \times 6 \times 3\text{ in}$ ($203 \times 152 \times 76\,\text{mm}$)	$7.5 \times 5.5 \times 2.8\text{ in}$ ($190 \times 140 \times 71\,\text{mm}$)	Rests flat centered on top of tray	Fraction Studio, Classroom Clock	USPS Ground Advantage (<12 oz)
Box Tier 3	$9 \times 6 \times 3\text{ in}$ ($229 \times 152 \times 76\,\text{mm}$)	$8.5 \times 5.5 \times 2.8\text{ in}$ ($216 \times 140 \times 71\,\text{mm}$)	Sits in dedicated lid pocket	SC-32 Hardware Maker Kit	USPS Ground Advantage (<16 oz)
Pouch Tier 4	$6.5 \times 4.5\text{ in}$ Stay-Flat Mailer	$6.2 \times 4.2\text{ in}$ ($158 \times 107\,\text{mm}$)	Encased with part in glassine sleeve	Single Replacement Parts, Volvelle	First-Class Rigid Mailer (<3 oz)

4. Fulfillment Bench Protocol: The 6-Step Packing Checklist

Before any shipping label is applied, every kit is verified against our 6-step bench protocol:

flowchart LR
    S1["1. Visual Audit<br>& SHA Hash"] --> S2["2. Gridfinity<br>Flush Seat"]
    S2 --> S3["3. Place Card<br>Side A Up"]
    S3 --> S4["4. Glassine<br>Eco-Wrap"]
    S4 --> S5["5. Box Seal<br>& Tamper Tape"]
    S5 --> S6["6. USPS Label<br>& Battery Exemption"]

Step 1: Visual Audit & Component Verification
Match every physical component against the Side A manifest table. Verify that the debossed Git commit hash on the tray base matches the active release.
Step 2: Gridfinity Flush-Seat Check
Seat all tiles, towers, or gears into their contoured receptacles. Gently tilt the tray 15°; components must remain firmly nested without rattle or shifting.
Step 3: Reference Card Placement
Lay the $135 \times 90\,\text{mm}$ reference card squarely on top of the components. Side A (Schematic & Inventory) must face upwards toward the recipient.
Step 4: Plastic-Free Protective Wrap
Enclose the tray and card inside a semi-translucent, biodegradable glassine sleeve or unbleached kraft tissue paper. Strictly zero plastic bubble wrap or foam peanuts.
Step 5: Box Closure & Tamper-Evident Seal
Close the corrugated mailer tabs firmly and affix a branded tamper-evident kraft paper seal across the front seam.
Step 6: Shipping Label & Postal Compliance
Affix the 4x6 thermal shipping label (USPS Ground Advantage). Confirm the Class 9 Lithium Battery Exemption text is printed:
NON-REGULATED - NO LITHIUM BATTERIES CONTAINED - 49 CFR / ICAO / USPS PUB 52.

5. Spiral-Bound Book & Student Workbook Fulfillment Protocol

To provide students with rugged, lay-flat laboratory workbooks without maintaining costly book warehouse inventory, StackCalc uses a Hybrid Zero-Inventory Print-on-Demand (POD) model governed by PLAYBOOK-OPS-01:

flowchart TD
    Order["Incoming Workbook Order"] --> Branch{"Order Type"}

    Branch -->|"Standalone Workbook (SC-BOOK-01)"| POD["Pathway A: Lulu Direct POD Drop-Ship"]
    Branch -->|"Tactile Kit Bundle (*-BNDL)"| Bench["Pathway B: Packing Bench Buffer (SHELF-BOOK-01)"]
    Branch -->|"District Bulk Order (10-30+ copies)"| Bulk["Pathway C: Bulk POD Run (Mixam / Lulu)"]

    POD --> POD1["Automated Lulu Direct API / xPress"]
    POD1 --> POD2["Zero local touch • Shipped in 24-48h"]
    POD2 --> POD3["Digital PDF license link emailed to customer"]

    Bench --> Bench1["Pull 1 copy from SHELF-BOOK-01 buffer"]
    Bench1 --> Bench2["Execute 5-Point Bench QA Audit"]
    Bench2 --> Bench3["Consolidate with 3D Gridfinity kit in single 12x9x4' box"]

    Bulk --> Bulk1["See District Purchase Order Playbook"]
    Bulk1 --> Bulk2["Dispatched directly to school front office"]

Essential Binding & QA Requirements

The Lay-Flat Desk Mandate: Laboratory workbooks must feature Wire-O or heavy-duty plastic coil binding. Glued paperback bindings (such as standard Amazon KDP) snap shut on active student desks and are strictly prohibited in StackCalc classrooms.
5-Point Bench Quality Assurance Audit:
Gate 1 (Spine Integrity): Loops fully circular and crimped; zero sharp wire snags or crushed teeth.
Gate 2 ($360^\circ$ Fold): Front cover folds $360^\circ$ behind the back cover with zero resistance.
Gate 3 (43-Page Completeness): All 20 CRA units, Singapore/Bridges concordances, and answer keys present.
Gate 4 (Punch Margin): Clean $0.5\text{"}$ spiral punch margin with zero text truncation.
Gate 5 (License Card): Slip physical Single-Teacher Reproduction License Card inside front cover.
Farm Tracker Integration: Integrated directly into the operations engine. Workbench operators can review the complete SOP anytime via:
```
python3 Tools/farm_tracker.py playbook spiral
```

6. School District & Institutional Purchase Orders (Net-30)

School districts, BOCES, charter networks, and private academies procure educational instruments and manipulatives through formal Purchase Orders (POs) operating under standard Net-30 terms governed by PLAYBOOK-OPS-02:

sequenceDiagram
    autonumber
    actor District as School District / Teacher
    participant Hub as StackCalc Procurement Desk
    participant Farm as Farm Tracker / Slant 3D API
    participant POD as Lulu / Mixam POD
    actor Office as School Front Office (Attn: Teacher)

    District->>Hub: Submit PO Document (Web Quote STK-PO-xxxx or Direct PO)
    Hub->>District: Return W-9, Direct Deposit ACH & Tax Exemption Review (<24h SLA)
    Hub->>District: Issue Digital Perpetual District License PDF
    par Hardware Production
        Hub->>Farm: Route Manipulatives (In-House Farm or Slant 3D API)
    and Lay-Flat Workbooks
        Hub->>POD: Trigger Lay-Flat Spiral Workbooks Dropship
    end
    Farm-->>Office: USPS Priority / UPS Ground Parcel Delivery (Direct to Front Office)
    POD-->>Office: Parcel Delivery (Attn: Teacher / Room #)
    Hub->>District: Electronic Net-30 Invoice with Tracking Numbers (<2h of dispatch)
    District->>Hub: Net-30 Remittance via Direct Deposit (ACH/EFT)

Institutional Operating Standards

Strict Parcel Delivery Mandate (No Freight Docks): All shipments are delivered as standard USPS Priority Mail or UPS Ground parcels directly to the school front office (Attn: [Educator Name], Math Dept / Room #). StackCalc never requires or utilizes freight docks, loading bays, or pallet staging.
24-Hour Vendor Onboarding SLA: Signed IRS Form W-9, EFT/ACH Direct Deposit authorizations, and FERPA/Texas DIR compliance statements are dispatched within 24 business hours of request.
Zero-Inventory Production Scalability:
Class Packs (1–15 Units): Scheduled through the in-house Prusa MK4S sprint queue.
District Fleets (16–100+ Units): Tactile Gridfinity trays and components are routed directly to Slant 3D's distributed farm API, while spiral workbooks drop-ship in volume via Mixam or Lulu.
Perpetual District Reproduction License (DIST-LIC-PERPETUAL): Includes perpetual multi-teacher reproduction rights, internal LMS hosting (Canvas, Google Classroom), and all 20 CRA unit answer keys.
Farm Tracker Integration: Operators can review institutional protocols and Net-30 remittance procedures via:
```
python3 Tools/farm_tracker.py playbook district
```

7. Downloads & Printable Packing Bench Sheets

Printable Packing Bench Sheet (Duplex HTML):
Open Printable Packing Bench Sheet
Product Catalog & Digital Decks:
Explore all product suites in the Master Catalog or browse Curriculum Decks.
Curriculum Alignment Matrix:
Review state and national curriculum alignments in the Curriculum Alignment Matrix.

Dimension	Specification	Engineering Justification
Width	\(135.0\,\text{mm}\)	Fits within \(150\,\text{mm} \times 150\,\text{mm}\) laser engraving working beds with \(7.5\,\text{mm}\) perimeter clamping margin.
Height	\(90.0\,\text{mm}\)	Fits inside standard \(6 \times 4 \times 2\text{ in}\) (\(152 \times 102\,\text{mm}\)) corrugated mailers with \(8.5\,\text{mm}\) finger extraction clearance.
Corner Radius	\(r = 3.0\,\text{mm}\)	Eliminates dog-earing, paper cuts, and friction snags inside corrugated boxes.
Aspect Ratio	\(1.50 : 1\) (\(3 : 2\))	Golden ratio matching standard photographic index plates and postcard standards.
Gridfinity Overlap	Spans 3x1 (\(125.5\,\text{mm}\)) and 3x2 (\(125.5 \times 84\,\text{mm}\))	Sits flush on top of organizer bins as an integrated dust shield and presentation layer.

Profile	Dimensions (Exterior)	Dimensions (Interior)	Reference Card Position	Compatible Products	Postal Class
Box Tier 1	\(7 \times 5 \times 2\text{ in}\) (\(178 \times 127 \times 51\,\text{mm}\))	\(6.5 \times 4.5 \times 1.9\text{ in}\) (\(165 \times 114 \times 48\,\text{mm}\))	Rests flat on top of 3x1 Gridfinity bin	Algebra Boxes, Ten-Frames, Dice & Spinner	USPS Ground Advantage (<8 oz)
Box Tier 2	\(8 \times 6 \times 3\text{ in}\) (\(203 \times 152 \times 76\,\text{mm}\))	\(7.5 \times 5.5 \times 2.8\text{ in}\) (\(190 \times 140 \times 71\,\text{mm}\))	Rests flat centered on top of tray	Fraction Studio, Classroom Clock	USPS Ground Advantage (<12 oz)
Box Tier 3	\(9 \times 6 \times 3\text{ in}\) (\(229 \times 152 \times 76\,\text{mm}\))	\(8.5 \times 5.5 \times 2.8\text{ in}\) (\(216 \times 140 \times 71\,\text{mm}\))	Sits in dedicated lid pocket	SC-32 Hardware Maker Kit	USPS Ground Advantage (<16 oz)
Pouch Tier 4	\(6.5 \times 4.5\text{ in}\) Stay-Flat Mailer	\(6.2 \times 4.2\text{ in}\) (\(158 \times 107\,\text{mm}\))	Encased with part in glassine sleeve	Single Replacement Parts, Volvelle	First-Class Rigid Mailer (<3 oz)