Combination paint.
A trade sample card from 1881 issued by William Waterall & Co., Philadelphia paint merchants, to show buyers their combination paint shades. The pictures are flat printed colour swatches in tilted chevron bands with numbered rows, plus a black-and-white engraved trade label of paint barrels. A designer could take the tidy grid of tilted swatches as a model for palette charts, colour-matching displays, or paint-can labelling.
