How to Make a Tack Rag. Tack rags help remove dust and other fine particles from the surface of objects. Use them before applying varnish, polish, sealant and stain.
Dip an old rag into clean water and squeeze dry.
Sprinkle with paint thinner and 3 tbsp. varnish.
Work into cloth until it's saturated with the mixture.
Make sure mixture is worked evenly into the rag before applying to surface.