Tapastic images can only be 940 pixels wide, horizontally. There is no way to submit something that's wider.
So you can shrink your picture down to 940 pixels wide, or you can rearrange the image so it fits better (for example, if you have several panels lined up next to each other, you could move those panels to be stacked on top of each other instead), or you can include a link to see the study on another website, in the size you want to post it.
Tapastic is just made for vertical comics, so it's a little bit hard to post other things here.
