To Erase a Rubber Stamp.—To take from paper the impression in red ink of a rubber stamp, first remove the oily material of the ink with ether or naphtha, then bleach the powder.

To Remove Dust from Polished Surfaces.—To remove dust, without scratching, from the finest polished surfaces, the Moniteur Industrielle says, take (by weight) of cyanide of potassium, 1 part; soap, 1 part; chalk-blanc de Meudon, 2 parts; water sufficient to make a thick paste.

Substitute for Gum.—A correspondent of the Papier Zeitung recommends the following for printers and others as a gum substitute: Take 2lb of good dextrine, pour over it half-a-pint of cold water and stir vigorously for about ten minutes; when the dextrine is thoroughly soaked put it over a fire and keep it continually stirred for about five minutes. The substance will then be of the consistency of milk. This condition is reached when the bubbles begin to rise, and the solution looks as if beginning to boil; boiling, however, must be carefully avoided. Now cool the liquid in a shallow wide vessel and add about l¾oz. of glycerine, and it is ready for use.

Management of Inks.—An American contemporary says:—The management of inks seems little understood by many printers. Printing ink is substantially a paint, triturated to extreme fineness, and laid on the paper by type. There are occasions, of course, when the least amount of color that can be put on is sufficient, but it generally needs more. Especially in one class of work, that of handbills and posters, whether highly ornamented or not, more is required. The first requisite in this case is that they shall catch the eye quickly, which cannot be done by hair-line faces or small quantities of ink. They should be charged with color. That they are not is frequently owing to the ignorance of the pressman. His overlays and underlays are not right. They cover too great a portion of the form, or underlie too much of it, and the whole object of having them is lost. Principal lines should have more impression than weaker ones, and this is generally better accomplished by underlays than overlays, for not only is the impression stronger, but the line will take more ink. The more slowly the impression is made, the blacker the line will appear, as the ink then has time to penetrate. It is a useful thing sometimes to run a piece of work through a second time, thus giving more color. House-painters do not finish a house at once, but lay on one coat after another until the requisite intensity is obtained. Especially should this precaution be followed in pale or weak colors, such as the various yellows. One great reason why this hue is hardly ever used by printers, except through bronzing, is that it always looks pale and ineffective on paper. The remedy for this is additional presswork. The color, in its various modifications with red and black, is very effective, as can be seen by looking at the leaves of trees in autumn, which are compounds of green, brown, red and yellow, the first soon disappearing and brown being the last.