THROW IT AWAY!

We get this question all the time about Tack Rags and they cause more problems than they prevent. A "Tack Cloth" is cheese cloth saturated with linseed oil. If not used properly it will cause fish eye in your paint.

It is only needed if the surface has lots of dust or trash on it and can't be blown off or dusted off. To use it properly it should be completely unfolded. Unfold every single fold and lift it by the middle and gently dust the surface. Never apply any pressure to the surface with the tack rag or it will transfer the linseed oil to the surface and now you're in trouble.

You are far better off to use two clean cloths and a can of "Prepsol" paint and surface cleaner. Use one cloth to apply the prepsol and another to remove it. Change cloths frequently to avoid cross contamination.

I doubt seriously if you ever really need to use a tack cloth on a model.