How would I do to set the opacity of a background image defined for the body part of a form without affecting other elements on that form ?
I tried several settings through my css stylesheet, but I can"t find a way around, everything on that form is rendered opaque.
The opacity property by definition applies to the block element, not the background image. What you need is a background-opacity property but it doesn’t exist yet.
The solution is to put a label on your form that fills the body part (with anchors as needed), send it to the back, and set its style class to: