Set of 3 botanical plates Geigy, horsetail, soda and purslane

Botanical plates from geigy weed tables. These are boards with weeds for a manufacturer of phytosanitary products. Copyright of the 1970s. Very fine and detailed drawing. Off-white background color (photos taken with a white background). Boards in the same color tones (horsetail, soda, purslane). Very good condition, the edges are very slightly yellowed for horsetail with the presence of tiny spots very discreet, you really have to be very close to see them (see photos) Dimensions: 29.3 X 20.5 cm. Shipping in suitable rigid cardboard envelope. Do not hesitate to contact me for any questions.