A layer of the cheapest kind of mushn placed over the face of the straw-board will prevent the pins from tearing the surface of the map if they happen not to be pushed in exactly straight. The use of cloth over the straw-board also permits of changing the pins many more times than would be feasible with straw-board without the cloth reinforcing.

.'• /.■

Reoiew 0/ Reiyttws

Fig. i88. Every Pin Dot on this Map Marks the Home of a Student of the University

of Cincinnati

By using a map printed in colors which do not photograph as black, the pins show up distinctly on the map

as a background

Before mounting a map the colors should be tested to make sure that they will not run in water. The map should then be wet all over, preferably by laying it flat for a time in a large tray. Use a flour-and-water starch paste, paper-hanger's paste, or library paste of the kind used in mounting photographic prints. Carefully remove

GRAPHIC METHODS

all wrinkles and press the excess paste out from under the edge of the map. Shrinkage of the map and of the moistened straw-board surface will almost certainly cause the straw-board mounting to warp unless care is taken to prevent warping. At the same time the map is pasted on the front of the straw-board, paste a sheet of wet wrapping paper on the back of the straw-board mount. The shrinkage of the wrapping paper on the back will eciualize the shrinkage of the map on the front of the mount. Place the mounted map on a flat table surface or on a smooth floor, and stack books or other heavy articles upon the mount over night or until thoroughly dry so that any tendency to warp in the drying may be overcome by the weights.