How to put a background picture to my form?

I see forms in the theme area with background pictures, is there a way for me to create a similar form with a customized background?

Yes, there is a way to change the background of your form using the Designer tool. Here's how:

1. In the Form Builder, click the Designer button.

2. Under the Design tab, click the Background Image drop down. You can change Page Background and Form Background here by clicking the upload icon. 

3. Here's how to change Page Background and Form Background using JotForm gallery. 

4. You can also upload your preferred image by going to Upload an Image tab.

Let us know if you need any further help. Thank you.