Hi @Sue3127,
Welcome to the Bunnings Workshop community, it is fantastic to have you with us.
I'd suggest you grab a roll of Kraft Paper and some masking tape.
Lay the paper over the glass panels, then trace the outline with a pencil. You'll want the paper to be slightly smaller than the panel so that the tape has something to stick to.
You can then cut the paper to size with some scissors and cut the tape to length for all four sides and stick it on. Make sure the tape is tight against the timber.
Once you have painted, peel the tape and remove the paper.
Check out How to use painter's tape for some further guidance.
Let me know if you have any further questions.
Jacob
