Foam sheets (for arts & crafts) (Brookline)

White foam sheets for arts and crafts, 8 1/2 x 11 sheets, almost a whole package of this:
https://www.amazon.com/gp/product/B089DT3TC9/ref=ppx_yo_dt_b_search_asin_ti...

I used it for insulation around window ac units (that I no longer have)