Dictionarium Polygraphicum. Containing. Polygraphick Dictionary. W. To make wood of the colour of Walnut-tree. To wash colours. Steeping of colours. To whiten green or grey flax.

Dictionarium Polygraphicum:
Or, The Whole Body of Arts Regularly Digested.
Vol II.
London: Printed for C. Hitch and C. Davis in Pater-noster Row, and S. Austen in St. Paul's Church Yard. MDCCXXXV.
1735
To make wood of the colour of Walnut-tree.
Dry the peels of walnuts in the sun, boil them in nut-oil, and rub the wood over with it.

To wash colours.
Put the colour into a glaz'd vessel, and put fair water to it plentifully, wash it well, and decant (after a while) the water, do this 6 or 7 times; at last put the water (being just troubled) into another glaz'd vessel, leaving the dregs at the bottom; then into this second vessel put more fair water, washing it as before, till the water (being settled) be clear, and the colour remain fine at the bottom. Before you take the colour out ofthe vessel, spread it very thin about the sides thereof and when it is dry, some of it will sall to the bottom, which keep by it self; but the remainder which sticks to the sides of the bason is the best of all, which with a feather strike off from the sides of the vessel, for it will be finer than any flower.

Steeping of colours.
Take a quantity of the colour and put it into a shell, and sill the shell with fair water, to which add some fine powder of alum, to raise the colour; let it thus steep a day and night, and you will have a good colour. Where note, saffron steep'd in vinegar gives a good colour, and the Venice berries in fair water and a little alum, or a drop or two of oil of vitriol, makes a fair yellow. But some colours are to be boil'd, as Brazile, logwood, turnsole, rinds of wallnuts, wood-foot, &c. these when boil'd are to be kept close stopp'd in glasses, till you have occasion to use them.

To whiten green or grey flax.
First make a lye of good ashes and unslak'd lime, and steep the fax in it for twenty-four hours; and afterwards add some sal-armoniac put inco the middle of some unslak'd lime, and a few warm ashes; pour off the water, and make a sharp lye, and boil the flax in this lye for an hour or two, and you will find it become very white and bright, and that the sal-armomac is fix'd.
When the flax has been steep'd in the lye, boil'd, and well dry'd, then it must be rinsed very well in running or river water, and blued and wrung out with the hands.