Use Your Phone as a Tracing Projector or Light Box
A light box shines through the paper. A projector throws an image onto it. A phone can stand in for both, but not in the same way — and knowing which one you are imitating saves a lot of frustration.
As a light box
Put the drawing on the screen, brightness up, lay thin paper on top. The lines show through and you follow them. Limits: your paper cannot be thicker than about 100 gsm, and your drawing cannot be bigger than the screen.
- Good for: small drawings, quick copies, tracing on cheap printer paper.
- Not good for: sketchbooks, watercolour paper, anything A4 or larger.
- Use a soft pencil and light pressure. Do not press a hard pencil onto a screen.
As a projector
Nothing is physically projected — the camera overlay shows the sketch on top of the live picture of your paper, and you copy what you see on screen. That sounds like a compromise but it removes every problem a real projector has: no dark room, no keystone distortion, no bulb.
- Good for: any paper, any size, any surface.
- Needs: a stable mount and even light.
- Bonus: you can flip, rotate, resize and fade the guide, which no light box or projector will do for you.
Getting a stable setup
- Mount the phone so it cannot wobble when you lean on the table.
- Tape the paper corners down.
- Light from the side, so your hand’s shadow does not fall across the page.
- Size and rotate the sketch, then lock it.
- Re-check the alignment every few minutes rather than after an hour.
If your traced drawings keep coming out slightly distorted, it is almost always the phone angle. A camera looking at the paper on a slant will stretch the guide — get the lens as close to straight-down as you can.