How to Edit Image Size in HTML on Tumblr. If your blog images are too large, users may have to scroll to see them. Make the images too small, and blog visitors might not notice them.

How to Edit Your Theme With HTML on Tumblr. Tumblr supports full customization for any free theme you choose, as well as wholly custom themes for your Tumblr blog. Themes on Tumblr are made by a ...