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The program I found had an image behind some labels and text fields.

I think I found a program that did that by googling. I can't remember the program's name.
Try looking for: java adding background image

I guess it is a question of who has control over what is painted in the JPanel? You or the layout manager.
Can you split the panel into a paint area and a textfield area?

If it works, then there is nothing to change, is there?
We'd need the code that does not work.

There needs to be code that shows your problem. I'm sure you can create the code needed for testing.

Can you make a small complete program(SSCCE) to show the problem. Something that compiles and executes. Your short <snip> doesn't show enough.