Clarity results automatically from the prototype, which is based on the shape of the rectangle. This, without going to extremes and producing a hardly legible text, can vary from a square to an upright rectangle with a 1:4 width-height relationship. If this proportion is expressed as 2:8, it is easier to divide the proportions of the letters by eye according to the golden mean, as we learned when drawing the human body. In lettering, the golden mean is, once again, the most satisfactory proportion. Here we can only outline the elements of letter construction. Writing and lettering is a special field in which expertness is gained only by much practice. Real mastery is a special gift, which, like every talent, reveals itself through an unusual predilection for the subject.
To make this exercise easier it is advisable to use squared paper. First draw an upright rectangle of 5 x 8 units, and divide it diagonally in both directions; then, as illustrated, draw in the ellipse. This is the basic proportion, the prototype, for capitals, which gives the construction of C, L, N, 0, Q, and Z. By quartering the figure we get E, F, H, T, K, and Y. (E and F seem disproportionately broad, but in certain technical alphabets, which must be constructed with ruler, set square, and compasses, they are allowed to remain so. In the next stage it will be seen that they are normally altered to a more pleasing proportion. These mechanically constructed alphabets do not even use the ellipse, but instead join half circles with straight lines. )
Lines joining the centers of the top and bottom of the rectangle diagonally to the opposite corners give the two triangles which make A and V and, when doubled, M and W. The C is made by cutting the ellipse where it meets the diagonals, and the G is made in the same way, both letters thus not filling the rectangle completely. All the other letters are narrower still. The E, F, and T can now be given their correct widths. The D is half the ellipse, plus an additional eighth, with a vertical. The other letters are formed using circles and half circles with a diameter of four units. Better proportions can be given to the R and B if they, too, have at least one added width unit; otherwise they would appear too narrow.
At this stage we are moving well beyond the scope of rigid mechanical construction; creative lettering is more than measuring and logic. Nevertheless, the skeleton, the. proportion of the golden mean, must not be forgotten. As we develop a more sensitively designed letter, it will be found that many have a center that differs considerably from the geometric center of the rectangle. In B, D, F, G, H, P, and R, the central horizontal is slightly above the geometric center, the lower part of the letter thus being rather bigger than the upper to give greater stability.
In K and Y the juncture of the diagonals is similarly altered. In S and B the two half circles are of different diameters. There remain J and U, which are made respectively of a half and quarter circle across five units.
We now must decide whether to keep each letter as a schematic shape built up of uniform elements, or whether to consider each letter individually. Experience teaches that individually designed letters are more quickly and easily read than those built up schematically. The latter emphasize the regularity of the rhythm, but other artifices can be used to recover this so that in artistic lettering one is able to concentrate on the individual shape of each letter. W and M are the most obvious examples. They are much pleasanter and more legible if they are narrowed by making the two outer strokes tend more toward the vertical than the inner ones.
Two very simple and legible forms can be drawn directly from the basic rectangle, but their shapes are not attractive. The illustrations show how to find satisfactory proportions from diagonals within the rectangle, and other values from divisions according to the golden section. In the end we come to quite imponderable alterations, since no good writing is made from uniformly very thin lines. Either we make block letters with uniform thick lines, or we use a flat brush or broad nib to combine thick and thin lines. Serifs can be added to these. All these resources change the balance of the letters, so that the artist's sensitivity must be brought into playas the deciding factor.
A 3 x 5 unit rectangle for the small letters, in printing called lower case, can be derived from the original S x 8 rectangle. Ascenders and descenders, such as the "tails" of P and D, stand in a 3:5 relation to the average height. The S:3 relation has already been used for the horizontal line in capital A, and small letters use the 3:5 relation in the same way as the 5:8 principle was used for the capitals. If necessary, the descenders and ascenders can be reduced to two units. The relation would then still be within the golden mean, though at the primitive level of 3:2.