Index bristol

From PyroGuide

Index bristol can be described as both a thin, strong kind of chipboard or a thick kind of paper. In pyrotechnics it is used for case liners inside traditional canister shells or insert components. Popular weights are 90 (0.007" thick) and 110 pounds (0.009" thick). Index bristol is popularly sold in large sheets as some sort of photo chipboard, white or manila in color. It has a grain.