If I recall correctly, there was mention that there would be a print version, so 6 5/8 x 10.25 is one of the confines to work within. This divides reasonably so that if done in halves, one 6 5/8 x 10.25 comic page can become two 480 x 640 pixel web "pages" with a little resizing and not too much difficulty. Just watch your text.