Find the column set on the KBS Paint Mixing Cup that matches the mix ratio in your paint's directions, such as 4:1. Each ratio has a Paint column, a Hardener column and a Thinner column, numbered 1 to 5. For a 2K paint, pour paint up to a number in the Paint column, then add hardener up to the same number in the Hardener column. For a 1K paint with no hardener, pour the paint straight up to a number in the Hardener column. If the directions call for thinning, add thinner up to the 10%, 20% or 30% mark at that same number in the Thinner column. Stir the mix thoroughly before you spray or brush.