How to Use Your Phone as a Lightbox for Tracing

Here's the reliable way to do it:

1. Open your image in a tracing app and set screen brightness to maximum.
2. Lock the touch input if your app supports it — otherwise your pencil strokes will scroll and zoom the image underneath.
3. Lay thin paper (printer paper or lighter) over the screen. Regular 80gsm printer paper works; cardstock is too thick.
4. Trace with a light touch. Use a soft pencil and minimal pressure.
5. Lift a corner of the paper occasionally to check your progress against the image.

Use light pencil pressure — you're transferring an outline, not engraving. A screen protector adds peace of mind, and avoid hard pencils (2H and harder) or anything with a sharp metal tip. If you're heavy-handed, put a sheet of thin acetate or a plastic sleeve between the screen and the paper.

The obvious constraint is that your drawing can only be as big as your screen. For anything larger than a phone screen, switch to the virtual projector method — same app, no size limit, and nothing touching your screen.

Stencly's Lightbox mode is built for this: it shows the image at full opacity, gives you a brightness control to make the lines shine through your paper, and has a touch lock so your strokes can't move the image. Combine it with the AI stencil generator to turn any idea into a clean line drawing before you trace.