ATC White Storage Box Ready-to-Alter, 125+ Count Cardboard Box. Artist Trading Card - 125+ Count Storage Box - White This storage box is the highest quality, cardboard storage box on the market today, and ready to be altered by you with paint, stamps, etc. . They are constructed of white corrugated paper and have a 200 lb. test strength. This box will hold up to 175 standard sized trading cards (200 is actually embossed on the inside bottom of the box, meaning that 200 plain baseball trading cards can fit inside of this box), but with bulkier ATCs, I would say you can hold more than 125, but could certainly hold more than that with 3 3/4 inches of space within the box. I guarentee the box for 125+. Bright white box measures 4 1/2 in. x 3 in. x 4 1/8 in. exterior and 3 1/2 in.x 2 3/4 in. x 3 3/4 in.