But, when you come to colour, the fact of the opaque middle tone (or half tone) being first painted over the whole will spoil the clearness and transparency of your shadows, and may also interfere with the brilliancy of the colour in the lights.  When colour comes to be considered it may be necessary to adopt many expedients that it is as well not to trouble too much about until a further stage is reached.  But there is no necessity for the half tone to be painted over the shadows.  In working in colour the half tone or middle tone of the lights can be made, and a middle tone of the shadows, and these two first painted separately, the edges where they come together being carefully studied and finished.  Afterwards the variety of tone in the lights and the shadows can be added.  By this means the difference in the quality of the colour between lights and shadows is preserved.  This is an important consideration, as there is generally a strong contrast between them, the shadows usually being warm if the lights are cool and vice versa; and such contrasts greatly affect the vitality of colouring.

Try always to do as much as possible with one stroke of the brush; paint has a vitality when the touches are deft, that much handling and continual touching kills.  Look carefully at the shape and variety of the tone you wish to express, and try and manipulate the swing of your brush in such a way as to get in one touch as near the quality of shape and gradation you want.  Remember that the lightest part of your touch will be where the brush first touches the canvas when you are painting lights into a middle tone; and that as the amount of paint in the brush gets less, so the tone will be more affected by what you are painting into, and get darker.  And in painting the shadows, the darkest part of your stroke will be where the brush first touches the canvas; and it will gradually lighten as the paint in your brush gets less and therefore more affected by the tone you are painting into.  If your brush is very full it will not be influenced nearly so much.  And if one wants a touch that shall be distinct, as would be the case in painting the shiny light on a glazed pot, a very full brush would be used.  But generally speaking, get your effects with as little paint as possible.  Thinner paint is easier to refine and manipulate.  There will be no fear of its not being solid if you are painting into a solidly scumbled middle tone.

Many charming things are to be done with a mixture of solid and transparent paint, but it is well at first not to complicate the problem too much, and therefore to leave this until later on, when you are competent to attack problems of colour.  Keep your early work both in monochrome and colour #quite solid#, but as thin as you can, reserving thicker paint for those occasions when you wish to put a touch that shall not be influenced by what you are painting into.

[Illustration:  Plate XXV.