The 3M Paint Preparation System (PPS) comprises calibrated mixing cups, flexible liners, lids with built-in filters, and locking rings. As freshly filtered paint is dispensed, the liner collapses. This allows the spray gun to be operated at any angle in any plane through 360, including fully inverted. Expensive, unused paint can be saved in capped liner for storage and subsequent re-use. Only one pot for mixing and spraying. Up to 70% saving of cleaning solvent. Faster system from mixing to disposal. Less operator exposure to solvents.