These tempered glass cutting boards from Amazon are a perfect fit for the largest Masterson 12×16 air tight palette box – The ones with the bright red or blue tupperware style lids. $7.50 each in a four pack. I can’t get plain glass in that size for that price locally at the glass shops. None of the kitchen ware sources in town have cutting boards this size.
They are 1/4″ shy of 12×16 which gives you about 1/8″ clearance on all sides inside the Masterson box. Get with your friends and share an order if 4 are too many for you.
Sure there are cheap alternatives to palettes. My main studio palette is a free tempered glass plate from an oven door.
The whole point of my post was that they fit the Masterson palette boxes perfectly, not that I thought they were a dirt cheap deal for a glass palette. For those who use them, this is a real bargain vs paying someone to cut one and temper it for you.