Please note that Lightfast values on our Intaglio Printmaker Traditional, Litho/Relief and Etching inks are given using the Blue Wool Scale and is applicable to when printed as a solid colour. This is not the same figure as will be achieved when extended and printed as a tint, mix or shade. The conditions in which the inks are shown, i.e. whether beneath museum or UV glass etc will obviously affect the degree to which these relative values will apply. Intaglio Printmaker is not responsible for how its inks behave over time as ultimately there are too many variables and variations in their application! If you have any questions about our inks before you buy, then please don’t hesitate to contact us directly! Thank you.