A new client wanted an iris on his wife's guitar.
My concern was getting enough "tooth" on the surface so the acrylic paint would stick. I asked the guy at Lowe's and he said to use steel wool. He said I didn't need to go all the way down to the bare wood, just lose the shine.
So I did that, then followed with a superfine sandpaper, just to make sure I could get a good stick. I'd made a stencil of the outline, so that was the only area I sanded. Put down a light coat of very thin white and let dry to make sure it wouldn't chip off easily. Also taped off the guitar so it wouldn't get any junk on it.
I think it turned out very well. Hope he likes it.