JerseyFactory-DTF
ShippedRoster in, film out. The nesting engine every jersey shop was doing by hand in CorelDRAW.
- Stack
- WinUI 3 · C# · .NET 10
- Version
- v1.0.0
- Film
- 22" · 24" · 30"
- Year
- 2026
Problem
Every jersey shop does the same thing: retype names in CorelDRAW, size them by eye, drag them onto a sheet, and pray the numbers match. The errors are only found at the printer, and by then the film is already spent.
Solution
Paste the roster. It nests the blocks onto the film automatically, reports the packing efficiency and the film used, and produces print-ready output with the mistakes caught before anything reaches a press. It is a production tool, deliberately not a design tool.
Architecture
WinUI 3 on .NET 10, EF Core + SQLite, SkiaSharp for the rendering. The licensing runs entirely offline against an ECDSA keypair. The app carries only the public half, so it can verify a key but never forge one, and the product name is inside the signed payload, so a Jersey Factory Pro key can't be relabelled into a DTF key. Updates ship through a signed manifest: even someone who took over the GitHub account could not point customers at a malicious download.
Challenges
Python emits DER-encoded ECDSA signatures and .NET assumes raw r‖s. Without forcing the DER format on the verify side, every licence key I issued was silently rejected, with an error indistinguishable from the customer mistyping it. That one is worth knowing before it costs you a day.
Outcome
Shipped at v1.0.0 and sold to print shops: direct download, licence key over WhatsApp, 23 automated licence tests. The one rough edge is SmartScreen. Without a code-signing certificate, Windows still shows an "unrecognised app" wall on first install.