Permeable paper changes how long you can work with a single palette load. The cellulose fibers in Masterson's palette paper allow moisture from the underlying sponge to migrate upward into your paint, keeping acrylics workable for days instead of hours. This constant hydration prevents the frustrating cycle of mixing colors, stepping away briefly, and returning to find them skinned over or hardened.

The system requires both components working together: the sponge holds water beneath while the paper's porous structure transmits that moisture directly to your paint without oversaturating it. Each 12 × 16-inch sheet provides generous mixing space for multiple colors and values. The sponge maintains even moisture distribution across the entire surface, eliminating dry spots that would otherwise accelerate paint drying in specific areas.

Replace the paper when it becomes too paint-saturated to transmit moisture effectively, typically after several painting sessions. Replace the sponge when it loses its ability to hold water evenly or begins breaking down. Both wear at different rates depending on how heavily you paint and how frequently you refresh the palette, so buying refills separately lets you replace whichever component actually needs it rather than both simultaneously.