They are inexpensive individually and determine whether the finish comes out clean.
Masking tape and film define the edges and protect what should not be painted. Automotive masking tape is designed for the temperature and for clean removal without leaving adhesive; general-purpose tape leaves residue that causes paint defects. Masking film and paper protect large areas.
Mixing cups and strainers are part of the paint system. Graduated mixing cups allow accurate ratios, and strainers remove undispersed pigment and contamination before the paint reaches the gun. Straining is not optional on metallic and pearl products.
Tack rags and prep solvents remove dust and contamination from the surface immediately before painting. A tack rag lifts the particles that cause fisheyes and dirt nibs; the prep solvent removes oils that would prevent adhesion. Both are used after sanding and before the first coat.
Sanding supplies cover the grits and forms used in preparation. Block sanding with the right block and grit progression is what makes a panel straight; skipping grits leaves scratches that show through the finish.
