Templates designed on our site are created for the Blogger template "Minima". Not only does this refer to the sizing, but also to the underlying code. In order for the backgrounds to work correctly, your blog MUST be in this format. To check your blog and make sure this template is selected:
1. Select Layout under your blog title on your dashboard.
2. Select Pick New Template.
3. If your blog is already using "Minima", then the first Template box will already be marked. If not, select "Minima" and save your selection.
4. Now your blog is ready to add a background.