I'm assuming that you are delivering a paint grade product. I like Phenoseal for most applications where you are touching up tight joints. It has an adhesive quality, tools easily, and lasts well. I use vinyl spackling by DAP (turns from pink to white) for nail holes. Generally, I like two coats of paint over nail hole filler. Always apply caulking to already primed surfaces. Caulking applied to bare wood shrinks and cracks.