Dictionarium polygraphicum. A transparent purple.

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
This may be made either redder or nearer the blue, as you would have it, by boiling four ounces of rasp'd Brasil wood in a pint of pale stale beer, and half an ounce of logwood or Campeachy wood, 'till the liquor is heightened to the colour you desire, which may be known by dipping a piece of paper in it.

If you find it too red, add a quarter of an ounce of logwood to the Brasil wood, and it will be much nearer to the purple than the former; and by this method you may humour it to any degree of purple, by putting in either more or less logwood to the former composition, and fixing the colour with alum.

This will produce such clear purple, as no mixture of solid reds and blues will produce, and the receipt has been for a long time kept secret.

Madam Mariana of Amsterdam, famous for painting in miniature, and her excellent manner of illuminating prints, says that the best purple that can be made, may be compos'd between the carmine and indigo; to strengthen which on the red side, you may add lake, between the lighter and darker part: and so lake, when it is us'd in the same way, on the foregoing purple, or tie liquid crimson, produces a very fine effect.

The colour of the purple may be varied, and made either redder by putting more carmine, or bluer by using more indigo; which being mix'd on a white Dutch tile, will shew itself.