Yes, we do offer PDF sample files for most of the formats we support. The samples are very useful to understand how the PDF that you submit should look like - in particular, the dimensions including bleed.
In order to download a template:
2. Find the product and the format you are interested in
3. Click on "Upload your print"
4. Click on "Download template"
We also offer an online design editor that you can use to upload your design and create products directly from our portal.