White fiber board?

someone left some thin white fibrous board pieces in the scrap bin.

it’s kind of like posterboard but thicker and more rigid. maybe a cardstock ?
the original sheet was mich larger than 8-1/2x11ih paper

I could use more of this stuff right away. does anyone know what it is and where to get it? looks like maybe an art supply?

Without having seen it, it sounds like matboard or a heavy watercolor paper. Chipboard also comes in several thicknesses (or plys) but is not white. Jerry’s Artarama has a good selection of specialty paper products like this

I think there’s someone around who cuts “museum board”, at least that’s what they called it. Sounds like what you’re describing

It’s not multimedia board is it? A heat set epoxy paper product that is brittle and cracks when bent but stays absolutely flat when wet.