THE COMB.
For the production of nonpareil marble, the comb is employed, made in the following way; take two strips of heavy pasteboard, 12 inches long and 2-1/2 inches wide, divide one of these exactly where the needles are to be inserted, draw grooves so that the needles can be laid in; glue the part in which the needles are to be laid, insert the needles in the grooves as aforesaid, and, after drying, the second strip of pasteboard, is glued upon the first.
The needles best adapted to comb making for use in comb marbling are fine pearl needles of steel; they are preferable to the common pins because they do not bend and do not offer any resistance to the size while drawing the colors, and also because they cut the colors easily without forming furrows.
The comb is so prepared that the pasteboard protrudes slightly at both ends, by this the movement of the comb is defined by the rim of the trough. It is advisable to prepare about three such combs with the needles separated from each other about 3/32, 3/16 and 1/4 inch respectively.