Sketch Clean Support

How do I use Sketch Clean?

  1. Open the app and tap Take Photo or Choose Photo.
  2. The app automatically detects your sketch, straightens it, removes paper tint, and extracts clean lines on a transparent background.
  3. Use the sensitivity slider to adjust how much detail is captured.
  4. Toggle Preserve light strokes to keep faint pencil marks or produce pure black lines.
  5. Tap Transparent to share the transparent PNG, or On White to share a version with a white background (better for Photos, Messages, and social media).

Tips for best results

Lighting

  • Use even, diffused lighting. Natural daylight from a window works well.
  • Avoid direct overhead light that casts shadows across the page.
  • Avoid shooting under warm/yellow bulbs — the app handles tint removal, but neutral light gives the cleanest result.

Framing

  • Fill the frame with your sketch. The closer, the more detail is captured.
  • Try to keep the camera parallel to the paper to minimise perspective distortion (though the app corrects moderate angles).
  • Leave a small margin of the desk/surface visible around the edges so the page detector can find the paper boundary.

Paper and media

  • White paper with dark ink or pencil gives the strongest results.
  • Light pencil (H, 2H) may require higher sensitivity.
  • Marker, pen, and brush ink all work well.
  • Coloured paper or very faint lines may produce weaker results — try increasing sensitivity.

What to avoid

  • Glare or shine on the paper (especially from glossy sketchbooks).
  • Fingers or objects overlapping the sketch area.
  • Crumpled or heavily textured paper.

What format is the output?

Sketch Clean exports PNG files with a transparent background (RGBA). This is compatible with Procreate, Clip Studio Paint, Photoshop, Affinity, and most digital art apps.

My saved image looks black in the Photos app

This is expected behaviour with transparent PNGs. The iOS Photos app shows transparency as black when viewing full-screen, so dark line art on a transparent background can appear invisible.

Your image is fine — open it in any art app (Procreate, Clip Studio, Photoshop) and the transparency will display correctly with a checkerboard pattern.

To avoid this, use the On White button instead of Transparent. This exports the same line art on a solid white background, which looks correct in Photos, Messages, and social media.

How do I open the result in Procreate?

  1. Tap Transparent in Sketch Clean.
  2. In the share sheet, tap Copy to Procreate (or open in Procreate).
  3. The image imports as a new layer with transparency preserved.

Alternatively, save to your camera roll via the share sheet, then insert from Photos in Procreate.

The processing result looks too faint / too dark

Adjust the sensitivity slider:

  • Higher sensitivity (right) captures more detail, including faint pencil strokes. May also pick up paper texture.
  • Lower sensitivity (left) keeps only bold, confident strokes. Cleaner result but may lose light marks.

Toggle Preserve light strokes on to retain pencil graduation, or off for pure black-and-white output.

The page detection didn’t work

If the app doesn’t detect your page and correct the perspective:

  • Make sure the full page edges are visible in the photo.
  • Ensure there is contrast between the paper and the surface behind it.
  • Avoid patterned or white surfaces that blend with the paper.

If detection fails, the app processes the full image without cropping — you can still get good results.

Does the app work offline?

Yes. All processing happens on your device. Sketch Clean never connects to the internet.

Is my data private?

Sketch Clean collects no data whatsoever. No analytics, no accounts, no tracking. Your sketches never leave your device. See our full privacy policy.

Contact

For questions, feedback, or bug reports:

hello@appsforlife.co.uk