Maps to be folded must be cut into sections of suitable size. In order that they may fold together well, the various pieces are set slightly apart, the horizontal lines slightly less (1 1/2 mm.), the longitudinal somewhat more, where there are many parts up to 3 mm. .
Perfect fitting is here essential, and to insure this it is advisable to mark out the divisions with the folder and rule. This is not necessary for small maps the eye will then be sufficient guide. Thorough rubbing down is absolutely necessary to make every part adhere.
When perfectly dry, the material is taken from the stretcher, the edges accurately trimmed, and the map folded upon the cross lines into one long strip, and then this strip is folded over in zigzag fashion to the given size.

The appearance of such a map is greatly improved by sharply pressing awhile, for which a zinc plate should be inserted between each fold.

Such maps are often placed in a small light case of cardboard covered with cloth, or a light cover is made, into which the map is so pasted at the back board that it lies ready for use when opened.

Paintings, drawings in color, or wash drawings cause exceptional difficulties, as the moisture of the pasting medium tends to dissolve or make the colors run. In such cases smaller sheets are placed between sheets of damp blotting paper, and it is stuck upon the pasted underside. When the object permits it, it is glued on without previous damping. Large tracings present the greatest difficulties as the paper stretches very much and, on account of its delicacy, is not easily manipulated and is liable to crease. Such work requires several hands. It is necessary to have clear paste, quite free from knots, which has been thinned to the consistency of thick pea-soup. When at all practicable, the tracing itself is pasted twice, the first pasting will make the paper stretch and the second ensures a proper coating of paste. Two persons lift the tracing and turn it over (for very large pieces four persons are required); the sheet is laid down at one corner, the other three being held up, and the whole gently lowered little by little. One person rubs it down slowly, proceeding from the first corner and carefully avoiding creases and bubbles.

With such big jobs it is often impossible to avoid tears near where it is held by the fingers of the workers unless timely precautions against this are taken. The simplest way is to paste strips of paper and to stick these on the four corners of the pasted side of the tracing and to take hold of these. These strips are removed as the rubbing down progresses, making sure, however, that there is still enough paste left on these places.

Tracings are always mounted upon white paper, even though it has afterwards to be cut or mounted on cloth.

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