The image above, printed on muslin, was found on the back of this Double Irish Chain quilt top. Barbara says this is probably a bolt stamp, like a selvage marking. It says: "Finished Soft for the Sewing Machine."
Above is an example of the paper bolt labels that were used in the 1800's. They became more elaborate as printing capabilities improved. Then, in the 1900's printing on the selvage became popular again. Read more on this topic at Barbara's blog: www.barbarabrackman.blogspot.com.
She even shows a selvage block by May Britt.