It gives the sticker a nice surface to bond to, Laminate isn"t really necessary unless you need the fill [to meet up with the Tmoulding]
Paint [usually my choice] needs to cure well before applying The art, Or you"ll get solvent pops [Bubbles under your new sticker]
Stencils are also a option [Depending on what game your building]. The games that put vinyl directly on the wood,[ Sega, enduro racer comes to mind,]
didnt fare so well, As far as adhesion goes.