I am decoupaging a poster to furniture in this video. I find posters are a lot different than other types of thinner paper. This method has worked great for me!
Great question. I did spray the laquer first - I have found by putting a light coat of lacquer followed by the clear coat - it keeps my paper from puckering. Since it’s more of a poster type paper than decoupage paper, it takes a little extra to make sure it stays adhered to my piece. I feel the lacquer by itself does not offer enough protection and wanted something more durable.