This section is from the book "Modern Buildings, Their Planning, Construction And Equipment Vol1", by G. A. T. Middleton. Also available from Amazon: Modern Buildings.
There are few more fascinating parts of a draughtsman's business than that of lettering up his drawings, or designing the lettering to be placed upon the inscriptions which are frequently used upon buildings. The first points to arise for consideration in this regard are suitability of style to the subject to be illustrated, the material in or upon which the lettering is to be done, and the tools to be employed, together, in the case of the work in a busy office, with rapidity of execution, and at all times absolute legibility. Often these various requirements conflict one with another, while at other times some are more prominent than are others, and some are occasionally absent. A good draughtsman will instinctively select the best style for the work immediately in hand, and will avoid the common faults of complexity, and of making his lettering to so small a scale that it is difficult to read.
Lettering has a history of its own, but for modern purposes it is unnecessary to go back further than the Roman. The ancient Assyrian arrow-head style of writing, the Egyptian hieroglyphics, and even the Greek and many more modern alphabets are useless in modern English practice, or are required only for very exceptional inscriptions.
The Roman style is that with which we are most familiar on the printed page, modern printers' type being a modification of it, with but little alteration. In two of its forms it is exceedingly useful to the draughtsman. Block lettering, whether upright or sloped, such as A B C or D E F, is amongst the clearest lettering which can be placed upon a drawing, and can be read even if it be exceedingly small. It is therefore most useful for drawings which are to be reproduced by photography to a smaller scale, as it remains legible when almost microscopic in size. The strokes, it will be noticed, are of the same thickness throughout, but the upright description is difficult to draw, taking a long time and needing great care. It is perhaps the best lettering of all for a student to start upon, as it trains him to exactitude more than any other. At the same time it is so slow that there are very few offices in which the time can be spared for its execution, and unless it be very well done indeed it looks bad, or at least commonplace. The sloped form is not quite so legible, but it can be much more rapidly written and need not be done with such extreme care, while its appearance is generally superior to that of upright block lettering. A judicious combination of the two will often produce satisfactory results particularly upon drawings which are of a practical rather than an artistic character.
The other form of Roman lettering which is in frequent use is that known as "Italics," as represented by the letters in which the word "Italics" is printed here. This is a form in common use amongst printers for purposes of emphasis, but it needs slightly altering if it is employed upon plans - as it frequently is, particularly by engineers. It is then made in small, or as they are called "lower case" letters, more like copper-plate handwriting, the letters being joined to one another, and some of them, such as " g," being of the handwriting character. Lettering of this description can be made legible, and written with extreme rapidity by anyone who is accustomed to it, while with the addition of a little artistic skill it may become pleasing. It has, however, been much more used upon mechanical than upon architectural work.
These are the forms which perhaps a student had best apply himself to at the outset, mastering and becoming perfect in them before he goes forward to anything more. It is upon them that he must obtain control over his pen, and learn to slope correctly. Before starting he should rule on his paper light pencil lines such as those in a copybook, indicating not only the upper and lower edges of the small letters, but also the terminations and the heads and tails of the extended letters, and the tops of the capitals. The longer extended letters are generally carried up to the same height as the capitals, and these are about 50 per cent. longer than the small letters and sometimes a trifle more. The small letter "t," however, only extends half as far above the ordinary line as any of the other extended letters. Besides ruling these guiding lines it is also advisable to rule a number of parallel pencil lines somewhat close together, but not necessarily equidistant, parallel to the slope. In other words, upright lettering should be ruled with a number of vertical lines, while slope lettering should have sloped lines inclined at an angle of about 70 degrees with the horizontal. These are only guide lines, and should be put in softly. A beginner will then pencil in everything that he has to write with extreme care, finishing the pencil work as if it were to be in ink; but as he gains control he will gradually cease using these pencil outlines, and will merely indicate in pencil where his letters ought to come so as to be sure to occupy only the correct spaces afterwards with his words. It is always well, however, to write every word in full, however roughly it be done, in pencil, and to carefully read it through afterwards so as to detect any accidental mistakes in spelling, which are much more likely to occur in slow lettering of this description than in ordinary rapid handwriting, the omission of letters being a very common mistake.
There is a great temptation when employing block lettering, whether upright or slope, to use the drawing pen for straight lines, but if freedom is ever to be obtained and a good effect produced the hand only should be employed. Inking-in is generally done with a steel pen. For block lettering a coarse rather than a fine point should be used, according to the taste of the draughtsman, but if a sufficiently broad point is selected to accomplish the straight lines in single strokes it is so much the better. Many draughtsmen, however, prefer to use a somewhat fine pen, drawing the outline first and afterwards filling it in, and for a beginner this is undoubtedly the better plan, as he is enabled to correct any little irregularities on the fine outline. The curved letters will probably give most trouble, particularly "S" and "O," and difficulty will be experienced in keeping the lines of equal thickness round the curves.