(From the Printer's Circular.)

To cut Paper into Three or Five Parts.—Mr E. J. Ring, Government Printer at New Orleans, says: If paper is to be cut into three or five parts, the old method of figuring after measuring, compassing, and guess-work, folding, &c., can be done away with by simply rolling the paper into a scroll until the ends meet twice, which marked with the finger-nail or pencil, gives one-third. If one-fifth is desired, roll the paper till the ends meet four times.

To Obtain correct Margin.—The same printer says: In job work, when an impression is taken on the tympan, and the pressman wishes a sheet to be printed in the centre, he has only to place the right edge of his paper at the right end of the printed line on the tympan, and mark on the sheet at the left end of the same line, and fold the remainder into one-half, marking the tympan at the left edge of the sheet to be printed. This does away with mistakes and guess-work. [We think most pressmen follow this plan.—Typo.]

(From the Pacific Printer.)

To Copy Printed or Written Matter.—Printed matter may be copied on any paper of an absorbent nature, by damping the surface with a weak solution of acetate of iron, and pressing in an ordinary copying press. Old writing may also be copied on unsized paper if wet with a weak solution of sulphate of iron mixed with a small solution of sugar syrup.

Harmony of Tints.—Gray sets off a color better than either black or white. White, gold, or black will serve as an edging to any color. A white ground has a tendency to make colors upon it appear darker, while a black ground has a contrary effect. In the association of two tones of one color, the effect will be to lighten the light shade and darken the other. The fact that incongruous colors are often harmoniously combined in nature is no guarantee that they may be similarly applied in art.

Spirits of Wine for cleaning off Copyable Ink.—To clean rollers used for printing copying inks, it is best to avoid water, which, it is claimed, weakens them, Spirits of wine proves much more efficient: it takes the ink off immediately, does not injure the rollers, and as it vaporizes almost instantaneously they may be used directly.

To Thin Copying Ink.—When copying-ink becomes hard or thick, as it will do on exposure to the air, it can readily be reduced to proper consistency by the addition of a few drops of glycerine. Add slowly, and test till right.

Basis for Ground Tints.—To make a good ground tint, use three pounds of magnesia ground up in a half a gallon of plate oil. This forms a transparent mass from which, by the addition of colors, as black, vermilion, lemon-yellow and bronze blue, innumerable tints may be manufactured, such as green, brown, lead, gray, buff, salmon, flesh-pink, purple, &c.

(From Austin Wood's Typographia.)

To find the Lay of the Type.—Fold a sheet of the paper and page it backwards, that is, page one on the back and page eight on the front.

When Cutting hard Paper and Boards, rub the edge of the knife with soft soap.

To put on a new Parchment.—Lay the tympan-frame upon it, cut out where the hooks and point-slides come, damp the edges two inches all round until limp, paste on as tight as possible. When the paste is dry sponge the parchment with a good drop of water; this prevents the parchment getting slack in damp weather.

To Prevent Electrotype Blocks from Warping.—To prevent electrotype blocks from warping, shrinking, or swelling, place them in a shallow pan or dish, cover with kerosine, and let them so soak as long as possible, say three or four days. Then wipe dry and place in the form. After the first two or three washings they may swell a little; if so, have them carefully dressed down, and after that you will have little or no trouble with them, and can leave them in the form just as you would if they were solid type.

Glaze Printing Inks.—In order to give printing inks a rich bronze-like appearance the following may be adopted: Take twelve ounces of shellac and dissolve in half a gallon of spirits of wine of a strength of ninety-five degrees. After standing for twenty-four hours, add seven ounces of aniline red, and leave it standing for a few hours. The liquid will then be ready for use, and may be added in small quantities to good black, blue, or other dark ink.