Dictionarium polygraphicum. Lapis Lazuli Japan.

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
1. Take Ising-glass size, or thick seed-lac varnish, and mix it with spodium, or white lead; and with this varnish your work 3 or 4 times over, laying it for a ground-work, letting it dry between each time.

2. Let it stand 2 or 3 days to be thoroughly dry, and then rush it, till it is very smooth, setting it by 2 or 3 days more after the rushing.

3. Then take thick seed-lac varnish at pleasure, mix it with fine pure blue smalt, with which varnish over your work 5 or 6 times, letting it dry between each time, then let it stand by for 2 days and rush it again.

4. When it has been rush'd smooth, varnish it twice over, once with the best white varnisb, and set it by to dry for 2 days more, then mix pure Ultramarine, or fine blue smalt, with the best white varnish, with which varnish it 6 or 7 times, till it comes to a full body, and a perfect likeness, letting it stand to dry between each varnishing.

5. At the last time of varnishing with the blue varnish, run all your work over stragglingly in wild, irregular streaks (in resemblance of nature) with liquid or shell Gold, filling the blue as you see occasion, and adding very small specks up and down, and such other various colours, as are usual to be seen upon the stone.

6. When this has been done, and the work is grown thoroughly dry, varnish it 3 or 4 times over with the best white varnish, letting it stand to dry between each time; afterwards let it stand 2 or 3 days, and then polish it with Tripoli, and clear it with lamp-black and oil.

7. You are to take notice of this, that by these methods you may make and use any colour you can fancy, or which reason and experience shall direct you to; but withall, that all colours that are light, and apt to tarnish and lose their beauty or gloss, with seed-lac varnish, must be covered and finish'd with the best white varnish, that of seed lac being prejudicial.