A diminishing glass, used to examine any drawings, will at once show the effect of reduction or diminishing, and in rough and rapid drawing this reduction is depended upon to remove irregularities and coarseness.[5]
IN HARBOUR.
Pen drawing. (Original 7 x 6.)
It may be taken for granted that nearly every reproduction we see has been reduced from the original, some more, some less, and while generally speaking we may say that the effect of reduction is to refine and soften; the beginner, however, will sometimes be troubled by finding an increase in the thickness of the lines which is less agreeable, and is very fickle, and can only to a limited degree be counted upon as to the result. Hence the need for keeping darkly shaded portions as open as possible: that is to say, when lines are very close together, or there is cross-hatching, see that the lines do not needlessly run into each other, but that the little white interstices are well preserved. Keep the shading open (the rough net-like effect can be got rid of by reduction), and remember that not only do some lines thicken up, and so engulf the intervening white, but in reduction the white spaces reduce as well as the black lines, and may be reduced into invisibility.
Some definite rules have sometimes been suggested to guide the process man as to the amount of reduction best suited for average work; these, however, like many other rules of the kind, are quite arbitrary. On this subject Mr. Henry Blackburn says, with an authority based upon the experience of reducing, to various scales, some thousands of drawings: "As to the amount of reduction that a drawing will bear in reproduction, it cannot be sufficiently widely known that in spite of rules laid down there is no rule about it."
Same size as original.
In some instances no reduction is required, and the reproduction is so exact a replica of the original that it can hardly be distinguished, yet, "On the other hand, the value of reduction for certain styles of drawing can hardly be over-estimated"; and again, "Every drawing has its scale, to which it is best reduced."