Flatton: An Online Utility for Creating Color Flats

Upload the line art Press 'Flatten Art' Save the file Place under line art

1. Upload .PNG File

TIP: Close open lines for best results!
TIP 2: Open hatched areas with a quick white line also.

2. Flatten Art

(Larger pages can take a minute, please be patient...)


Example: creating color flats for an illustration.

This online utility allows you to quickly flatten an inked illustration. You send an image with line art and Flatton fills each white area with a random color. It then grows each area so that it bleeds under the line art, touching the other neighboring areas.

Don't worry! Those are not the final colors! They were chosen to be dull middle tones on purpose, so you can tell which areas you need to choose a color for still.

You can change the colors with the bucket fill tool in your favorite drawing program. Just place the flat colors underneath the line art and set the line art layer mode to 'multiply' so the color shows through. Duplicate the color layer so you have a backup, and start changing the colors in the color layer.

  • Flatton will close opened lines if the opening is four pixels or less, but if lines are open in certain places, you can direct the flatting by closing lines first in the image you send, for best results. (You don't need to use the version with the closed lines for your final image of course.)
  • You can also open up crosshatched areas with a quick white line, to open up areas that should have the same color.
  • Areas that are marked red were initially too small, and were then either grouped into areas that were too big to remove, or they had more than one neighbor so Flatton could not decide which area to group them with.
  • Flatton occasionally returns 'indexed' .PNG files for reduced file size. You may need to change the image to RGB mode before you can use it.
  • As the colors used by Flatton are very close to each other, make sure you set 'Tolerance' to zero before using the bucket fill or magic wand tools in your favorite digital drawing software.

Currently only png is supported. The input file should not be larger than 20Mb and it should not have more than 80 million pixels - 8000x10000 pixels for example, which should cover an A3 at 600dpi.

I reserve the right to log images for diagnostic purposes. I try to remove those images from the server after diagnosis. Otherwise, no images are stored on the server. The entire operation is done in-memory and the resulting image is returned to your browser.

If you do worry about trusting this server, you can also use the free open-source offline version of Flatton, which is available here. You can inspect the code yourself and use this version to flatten your line art locally on your own computer.