What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
You can use your own jpeg as a background image via "advanced design" panel. In order to access this panel please edit your form and click on the "Design" button.
You will see the "Advanced Designer" button at the bottom of the pop-up page.
You can use your own background image by using this option:
Also, we have some user guides which are related to this topic.
I hope these helps.
If you need further assistance, please let us know.