[delta_p_delta_x]

> There are still differences between PDFs in different viewers

Most obvious when viewing PDFs in Adobe Reader versus in Chrome's built-in viewer. The former has subpixel anti-aliasing. The latter doesn't.

[cozzyd]

I think it's better now but PDF viewers used to ignore the interpolation method for bitmaps, resulting in colormap histograms turning super blurry depending on how they were saved. Oh and 0 width lines...