what is the best image size for my form background

In Video Submit Form what is the size of the background page image

The background size of your form depends on the size of your form.  If you have an image you would like to apply, it can be stretched to compensate for the size of the form. 

If you are having trouble applying an image to the background of your form or with getting it to fit, let us know what image you are trying to apply to which form and we will be happy to help.