Q. What belongs to the third part, or finishing?
A. It is supposed the complexion now wants very little more than a few light touches. Instead of oiling, as preparation for the third painting, if the colours are sufficiently dry, a soft sponge with clear water may be passed over the whole, and wiped off with a silk handkerchief.
Begin with the glazing, and first, where the shadows want bringing up to their tone and colour; improving also the half tints by a tender tone, and putting in the highest lights with a sharp and spirited touch, using the colour as dry as possible.
It must be observed that in putting in the highest lights, while the underneath colour is wet, they will sink in and lose much of their brilliancy. It is thought that most of the great masters touched upon their pictures many times, leaving them to dry between.
Q. Is this kind of repetition useful in all painting?
A. It will be found so, as every colour (more especially when mixed with white) sinks into the ground on which it is painted, and, in a greater or less degree, according to the colour of that ground. So it will be found necessary to repeat the same colour more than once, in order to bring it up to the tone required.¹
It is supposed the Complexion now wants very little more than a few light Touches; therefore there will be no Occasion for oiling.
Begin with correcting all the Glazing; first, where the Glazing serves as a Ground or under Part; then we should determine what should be done next, before we do it, so that we may be able to make the Alteration on the Part with one Stroke of the Pencil. By this Method, preserve both the Glazing and the Teints; but if it happens that we cannot lay such Variety of Teints and finishing Colours as we intended, it is much better to leave off while the Work is safe and in good Order; because those few Touches, which would endanger the Beauty of Colouring, may easily be done, if we have Patience to stay till the Colours are dry; and then, without oiling, add those Finishings with free light Strokes of the Pencil.
I believe that Rembrandt touched upon his best Pictures a great many Times, letting them dry between: It was this Method, most certainly, which gave them that surprising Force and Spirit, which is so inimitable. I find it much easier to soften the over-strong Teints when they are dry, than when they are wet; because we may add the very Colours that are wanting, without endangering the dry Work. If any of the Colours of the Pallet want to be a little changed to the Life, when we are painting, it is much better to do it with the Knife on the Pallet, than with the Pencil; because the Knife will mix, and leave it in good Order for the Pencil.²
¹ William A. Pinnock, A Catechism on the Practice of Painting in Oil, (Mentorian Press, London, 1817), pp. 17-18.
² Thomas Bardwell, The Practice of Painting, 1756, pp. 15-16.