In making their drawings for reproduction by line blocks, authors have at their disposal the black line, the white line, the black space, the white space, the black dot and the white dot, all of which may be combined in various ways. No tones, other than black and white, are available; if it be desired to represent half-tones, they must be rendered by the above-mentioned means. In the majority of cases the originals should be made with black ink on white Bristol board or smooth white paper; ordinary lead pencil drawings on smooth paper are useless, and lead pencil, black crayon or charcoal in combination with grained paper or board should not be employed unless the draughtsman has the requisite skill and knows exactly the limitations of the line block. For all ordinary folk black ink and Bristol board cannot be improved upon. The drawing may be made first with a soft lead pencil, using the camera lucida or other optical aids to correct delineation. The pencil lines are then gone over with ink; for this purpose a good black ink is necessary. Wolff's Indian ink, Higgins' waterproof ink and Steuber's waterproof drawing ink are highly satisfactory, and there are many others. With regard to pens, a suitable implement is all-important; Gillott's lithographic pens and Brandauer's No. 515 are recommended. For straight lines of an even thickness a ruling pen is very useful, and these may be obtained fitted with an adjustment which enables the worker to rule a line of a definite thickness, _e.g._, .5 mm. and so on. All drawings should be made larger than it is intended the reproduction to be, for slight inaccuracies, ragged lines, and other blemishes will thus appear less obvious. This drawing on a large scale is often a stumbling block, because the work appears too open and the draughtsman is tempted to put in too much; this must be avoided, else the crowded lines may join together in the reduced reproduction. Also it must be remembered not to draw too finely, else the work in parts may disappear entirely in the reproduction. In drawing on an enlarged scale a certain amount of exaggeration may be employed, in order that when reduced the drawing may not be quite spiritless. When representing a solid object, such as a plant or an animal, to shew the external morphology, it is to be borne in mind that form is the main thing to represent, and this can be expressed by outline drawing alone. In fact, more or less primitive methods must be employed, and better models cannot be followed than the best wood cuts. [Illustration: Fig. 9. The Lesser Celandine (_Ranunculus Ficaria_). By R. G. Hatton. (From Hatton's _Craftsman's Handbook_).] [Illustration: Fig. 10. The Lesser Celandine. After Fuchs. (From Hatton's _Craftsman's Handbook_.)]