An R value represents the insulation property of certain types of material that have a numerical value. This numerical scale system is used to determine the correct amount of insulation necessary to properly regulate heat/cooling loss and heat migration. AmCraft manufactures R-value insulated curtains for a variety of applications in the workplace. The requirements of your temperature control situation will determine which insulated curtain will work best: light insulation (R1-R4, temperature differential up to 10-15°), medium insulation (R8-R15, temperature differential up to 25°) and heavy insulation (R15-R27, temperature differential up to 40°). AmCraft manufactures retractable insulated curtains that have R-values ranging from R1 (lightest) to R10 (heaviest).