Scientific American 4, 14.4.1849
Wet the muslin and stretch it on a frame until it is dry. Wet the lithograph with weak gum water on the back side in an evenly manner with a large soft brush, this must be done very nicely, and then let it dry. Take some very fine flour paste and brush it over the muslin, and then put on the lithograph.
The gum will prevent the paste skriking through the print, which would injure it, some prefer fine gum to glue, and to it we give the preference, but glue is the common article used.