get your board and then route out the numbers/letters, then spray the numbers the color your want. Now, with a belt sander sand off the board and the sign will be clean wood. Now pour carefully mineral oil into the routed letters and numbers. The oil will pond because the paint has clogged up the pores and will not soak in. Now, carefully spray the sign. Let it dry and then dump off the mineral oil and you have a sign. Wipe out the routed figures to clean off the shine.