[Trying to remove white background from line art]

Thanks everybody.

 

[Trying to remove white background from line art]

It's the lasat one, firstdefence. I can see the texture of the white paper.

[Trying to remove white background from line art]

Hello.  I have pdf files from scanning my line art and I want to remove the white background. Using Affinity Photo, I went to Filters, colors, remove white paper. It looked right on the screen, with the grey checkered background, but when I exported it as a pdf, it still has the white paper background. I tried exporting iit as a png but the problem is still there. Help!