Transparencies for four-colour printing

Set of four overhead projector transparencies in the colours yellow, cyan, magenta and black, the principle of four-colour printing (i.e. printing presses and colour copying machines) may be demonstrated by overlapping transparencies, includes a durable, acrylic base plate with metal tongues for holding the four transparencies
Transparency dimensions: 30x20 cm, base plate: 30x28 cm