Are My Botanicals Light fast

This ingenious little cardboard wallet can be used to check if your botanical colours are light fast. A test sheet of the dyes you want to check is prepared on water colour paper. The dyes are named on the sheet for reference. Half of the test sheet is inserted into the pocket and the whole is left if bright sun for several days - the dashboard of a car parked in the sun in a good option. The wallet is simply made from packing cardboard folded over and taped along one long side and the two shorter sides. It needs to be short enough that the inserted test sheet is partially in the wallet and partially exposed to the sunlight