Occasionally, I receive calls from manufacturers experiencing "bleed through" when laying up veneers. Bleed through is the result of moisture in the adhesive carrying glue solids through the pores of the veneer to the surface. This usually results in finishing problems. Bleed through normally occurs when using porous species such as oak but can occur with any veneer. The major cause is a heavy glue spread. By minimizing the spread you can lessen the bleed through. Additionally, allowing some open time after the adhesive has been applied to the substrate will result in less bleed through. Finally, the use of a "filled" adhesive can help prevent bleed through by clogging the pores of the wood.