[klondike98]

Walnut has open pores and will benefit from grain filler while, as Ron mentioned, the other wood does not have open pores so no need to fill. There are a number of grain filler products out there and numerous posts on the Phorum about how people have gone about filling. It does take a bit of practice. Lately I've used Timbermate to grain fill. Its water soluble, easy to work with and easy to sand. For me it takes a couple of passes to get the grain filled completely. It comes in multiple colors so you should be able to match the wood pretty closely. People often lightly sand the veneer and apply a sanding sealer before doing the grain filling. This helps keep the filler from staining the wood surrounding the pores if its a staining type of filler. some fillers are oil based and different people have their favorite way of doing the filling.