Corrugated Cardboard is probably the least expensive material for prototyping. This is plain old corrugated cardboard. Universal, Epilog, Glowforge, Boss, Trotec, Dremel, Orion, FSL, Muse, Full Spectrum. Laser cutting is no problem. Pack of 12.
36 Corrugated Cardboard Sheets 12 x 12 Inches Brown
2 Pack 12 Feet x 35 Inch Corrugated Cardboard Roll
Staples 48 x 24 x 12 Shipping Boxes 32 ECT Brown 10/Bundle
HGP 9 x 12, 100 Pack, Corrugated Cardboard Sheets
Low-Risk Investing in Cardboard Stocks - Cabot Wealth Network
MECCANIXITY 100Pcs 12x12 Large Corrugated Cardboard
Golden State Art, 50 pack 9x12 Corrugated Cardboard
INCLUDES: Package includes 25 boxes per bundle. Boxes ship flat to save on storage, space and shipping. Corrugated boxes are reusable and recyclable.
Choice Shipping Supplies 12 x 12 x 13 Corrugated Cardboard Boxes, Kraft, Pack of 25, for Shipping, Packing and Moving, by Choice Shipping Supplies
MECCANIXITY 100Pcs 12x12 Large Corrugated Cardboard
12 x 12 x 20 Corrugated Cardboard Boxes (Brown / Kraft) - Sandbaggy
Partners Brand 16x12x12 Corrugated Cardboard Boxes, 16
PARTNERS BRAND 20 x 12 x 3 Corrugated Cardboard Boxes
Golden State Art, 50 pack 9x12 Corrugated Cardboard