From 3D printers to ebooks: what you can make off screen
August 25, 2026
* The first four are physical. The servers at the end run behind the screen.
Things you can hold
| What it takes | |
|---|---|
| 3D printing | An STL file. Print shops handle it if you have no printer |
| Raspberry Pi and Arduino | Parts, on the order of tens of dollars |
| Print and merchandise | A print-ready PDF |
| Ebooks | PDF or EPUB |
3D printing
STL is a file format that holds a 3D shape. It can be generated from code.
- Verified: an STL file was generated from code
- No printer needed. Plenty of shops print from a file you send
- Good for: character figures, parts, display models
Raspberry Pi and Arduino
A computer the size of your palm, and a control board smaller still. Attach sensors, load code, and it becomes an object.
- Cost: parts on the order of tens of dollars
- Good for: something that stays powered all day, a single-button device, sensors around a room
- Blocker: it needs power and a place to sit. Unlike software, failures are physical
Print and merchandise
Stickers, postcards, calendars, shirts. Print-ready files can be generated from code.
- Verified: a print-ready PDF was generated from code
- Blocker: print colors differ from screen colors. Bleed margins and color mode have to be set
Ebooks
Both PDF and EPUB can be produced from code.
- Good for: comic collections, course material, guides
- Blocker: EPUB reflows differently on every device. PDF is safer when there are many images
Servers behind the app
| What it is | When | |
|---|---|---|
| Firebase | Storage, auth, and hosting together | Starting out. The least setup |
| Cloudflare Workers | Small servers distributed worldwide | Generous free tier. Scheduled jobs and relays |
| Supabase | A relational database with auth | When queries get complicated |
| WebSocket | Many people at once, live | When several people watch the same screen |
| WebRTC | Video and voice calls | When people see each other |
| Serverless cron | Jobs that run at a set time | Pulling data in every day |
Choosing between them
Firebase bundles storage and auth, so it takes the least setting up. It's weaker on queries with several conditions, and that's usually where projects move to Supabase.
Cloudflare Workers fits scheduled jobs and relaying other services. The free tier is large enough that small tools cost nothing.
WebSocket is needed the moment several people watch the same thing live. A single-user app has no use for it.
- Blocker: the moment a server is involved, the privacy policy grows
- Blocker: free tiers are usually generous. What happens past the limit differs by service, and that's the part worth reading
What's been verified
| Actually produced | STL files, print-ready PDFs |
| In use | Firebase |
| Conditions checked only | Raspberry Pi, ebooks, the rest of the servers |