Gang Sheet Lab: Revolutionizing Print-on-Demand
An intelligent auto-layout engine with real-time preview—built for Shopify print shops shipping gang sheets at scale.
500+
Active merchants
4.8★
App Store rating
10k+
Orders processed
The challenge
Manual gang sheets were slowing production
Print shops struggled with manual gang sheet creation, wasting hours on layout design for every order batch.
- Time-consuming manual layout in design tools
- Error-prone spacing and bleed settings
- No automation from Shopify orders to print files
Our solution
Approach & timeline
We built an intelligent auto-layout engine with real-time preview, variant-aware pricing, and one-click print exports tied to Shopify orders.
6 weeks from concept to App Store launch
Why MERN Stack
MongoDB stores complex layout JSON and shop sessions; Express handles webhooks and file queues; React powers the embedded builder UI.
Why Remix.js
Remix loaders keep Shopify session auth on the server, stream fast embedded admin routes, and colocate actions for saves and exports.
API architecture
Shopify Admin API syncs products and orders; a dedicated file-generation worker produces PNG/PDF/SVG exports asynchronously via webhooks.
Product
Features showcase
Custom product builder
Merchants configure sheet sizes, margins, and upload zones. Customers drag artwork into cells with live bleed and safe-area guides.
- Variant-linked pricing rules
- Mobile-friendly storefront widget
- Artwork validation before checkout
Automatic nesting algorithm
Our nesting engine packs multiple customer designs onto a single gang sheet, maximizing material usage while respecting rotation and spacing rules.
- Bin-packing with collision detection
- Configurable gutter and bleed
- Preview before commit
Designs rotate and pack to minimize waste while respecting bleed zones.
Print file export
Production teams receive print-ready assets attached to orders—no manual export from design software.
- PNG 300 DPI
- PDF with crop marks
- SVG for laser workflows
Order management integration
Orders/create webhooks trigger layout regeneration; staff see status, reprints, and file history inside Shopify Admin.
- Webhook idempotency keys
- Order metafields for file URLs
- Bulk re-export for revisions
Engineering
Technical architecture
Embedded Remix app, Node API, MongoDB, Shopify layer, and an isolated file-generation service for heavy exports.
Frontend
- Remix.js embedded app
- React builder canvas
- Shopify App Bridge
Backend
- Node.js / Express API
- Webhook handlers
- Bull job queue
Database
- MongoDB layouts & shops
- S3 print file storage
Shopify layer
- Admin REST + GraphQL
- Orders & products sync
- Billing API
File generation
- Sharp / PDFKit pipeline
- Async workers
- CDN delivery
export async function handleOrderCreate(payload: OrderPayload) {
const layout = await LayoutService.findByLineItems(payload.line_items);
if (!layout) return;
await exportQueue.add("generate-gang-sheet", {
shopId: payload.shop_id,
orderId: payload.id,
layoutId: layout.id,
format: ["png", "pdf"],
dpi: 300,
});
}export const action = async ({ request }: ActionFunctionArgs) => {
const { admin, session } = await authenticate.admin(request);
const form = await request.formData();
const cells = JSON.parse(String(form.get("cells")));
await LayoutRepository.upsert(session.shop, {
cells,
sheetSize: form.get("sheetSize"),
updatedAt: new Date(),
});
return json({ ok: true });
};Impact
Results
Layout time per order
Manual errors
Merchant efficiency
- Reduced layout time from 2 hours to 5 minutes
- Increased merchant efficiency by 95%
- 10k+ gang sheets generated without designer handoff
“Gang Sheet Lab transformed how we handle custom print orders—builders love it and our production team finally gets clean files every time.”
Product tour
Gallery
Click any screenshot to open the lightbox
Built with
Tech stack used
Remix.js
Embedded Shopify app routing and server actions
React
Interactive canvas and real-time preview
Node.js
Webhooks, queues, and file APIs
MongoDB
Flexible layout documents per shop
Shopify API
Products, orders, and metafields
Sharp / PDFKit
High-DPI print asset generation
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We design and ship Shopify apps, AI features, and automation systems like Gang Sheet Lab—from idea to App Store.