A wet palette is a device that keeps your acrylic model paint “wet” for a near-indefinite amount of time. Just add water to the sponge material in a wet palette, and your paints won’t dry out, ever.
A potential limitation with using a wet palette over a long period of time is mold and bacterial growth. But, this is easily remedied by cleaning the palette often.
A major advantage for using a wet palette is that it can improve the way you paint miniatures with acrylic paint. Glazing and other advanced paint blending techniques are easier to learn and master when your paint doesn’t dry up on your palette.
You can buy commercially available wet palettes on the market. Or, you can make your own the DIY (do-it-yourself) fashion.