_The Place of the Inscription._--The actual space for a wall inscription is commonly suggested by an architectural feature--a stone, a panel, or a niche--of the wall; but in choosing a suitable space for a given inscription, or suitable lettering for a given space, we must take into account--
1. _The office of the inscription._ 2. _How it is to be read_-- (_a_) _"At a glance," or_ (_b_) _by close inspection_. 3. _The distance from the reader._ 4. _The lighting of the space._ 5. _The character of the surroundings._ 6. _Any special features._
_The Size of the Letters._--The all-important question of readableness may be settled thus: the inscription having been planned suitably to fill the space, one or two words are written or painted (the exact size) on paper--smoked or otherwise coloured if necessary to resemble the background. This is stuck upon the chosen part of the wall, and then viewed from the ordinary position of a reader. When the inscription is high up, the _thin_ parts--especially the horizontals of the letters--must be made extra thick to be seen properly from below.
_Margins._--_Wide margins are only required for comparatively small lettering which demands the close [p352] attention of the reader_,[103] and generally a set inscription looks best if the lettering be comparatively large--covering most of the given surface, and leaving comparatively narrow margins. The frame or moulding, or the natural _edge_ or environment of the circumscribed space, is very often sufficient "margin" (see Plate XXIV.).
The margins vary, however, according to circumstances; especially the foot margin, which may be very narrow if all the space is required for the lettering (see fig. 211), or very large[104] if there is plenty of space (see fig. 210). And, as in special pages or _terminal pages_ of books, so in _single sheets_, _panels_, &c., the "foot margin" may show--as it really is--as _the space which did not require to be filled_, and was therefore "_left over_."
_Number of Different Types._--While in a book of many pages considerable diversity is allowed, it is essential to the strength and dignity of a single sheet or set inscription to limit the number of types employed in it. Three or four ordinary types will generally give sufficient variety, and if it be necessary--as in notices and placards--that IMPORTANT WORDS be put in _special_ types to catch the eye, let two--or at most three--special types suffice, and let the remainder of the text be as quiet and reserved as possible. "Display Types" commonly defeat their object by being _overdone_. A simple contrast is the most effective (fig. 197). [p353]
