top side of the letter scale
In 1987 Theodorus C.W.M. Koster & Aart J. Roelandt, from Amsterdam in the Netherlands designed this letter scale. In February 1988 an application was made for an American design patent. On December 10, 1991 a patent with number Des.322229 was granted. The scale shown here was a promotional gift of ptt post, that no longer exists under that name. The letter scale has the familiar red color with bright white lettering of ptt post. The scale is 9 centimeters wide and 15 centimeters long. The thickness is 4 millimeters, the three protrusions on the bottom side are also 4 millimeters high. It is typical a design scale: looks nice, yet functional is different. A letter does not remain in the slots, always the letter should be held up by a hand. This may obscure the weighing result. Later this rocker letter scale was made in other colors as well, and also the printing was done in multiple colors. Colors used for this letter scale were among others: red, white, black, blue, and silver.
Below some more pictures of this rocker letter scale.
letter scale bottom
