Here’s a typical four panel comic strip:
To make your comic, you will make five images: one for each panel, and one of the assembled comic strip. The simplest way to make sure the panels will fit together is to make them all the same size. Make them fairly large to simplify editing them. The sample below is 1000 pixels wide and high.
When you’ve finished the panels, make a document that large enough to fit all four images with a little space between the panels . That space is called a “gutter.”
Because the individual panels are 1000x 1000, the full comic is a little more than twice that size (about 2050 x 2050).
One thing that’s missing is the borders around the panels. To add them:
Put all the panels into a group.
Double click to the right of the name of the panel group.
Select stroke, and make the line a thickness that you like.