3 8 Foam Core Board, I would think Gator Board which is much

Foamboard vs Gatorboard

Gatorfoam® Board

A Helix in Foam Core – Small Model Railroads

Foamboard vs. Gatorboard: What's Best for You!

Foam Core Signs, Foam Board Printing

Foamboard vs Sintra Board

Foam board is a lightweight, sturdy material for Indoor Use. Foam Board comes on white material (white sides and back).

Foam Core Printing | 3/16

Gatorboard Mounting & Printing

Shop for 3/16 inch black foam boards online at . Our black 3/16” thick foam board collection features dozens of different pre-cut sizes

Pre-Cut 3/16-Inch Black Foam Boards

Gatorboard vs Foam Core - Learn the Difference

Gatorfoam® Board - 48 x 96, Black, 3/16 thick S-13741 - Uline