I was recently seventeenth century researching fishing and found this instruction for making a waterproof boot polish.
I have a willing mind with Gods help to preserve all those that love this recreation, to goe dry in their boots and shooes, to preserve their healths, which one receit is worth much more than this book will cost.1
First, they must take a pint of Linseed oyle, with half a pound of mutton suet, six or eight ounces of bees wax, and half a pinniworth2 of rosin, boyle all this in a pipkin together, so let it coole untill it be milk warm, then take a little hair brush and lay it on your new boots; but its best that this stuff be laid on before the boot-maker makes the boots, then brush them once over after they come from him; as for old boots you must lay it on when your boots be dry.
It comes from BARKER’S DELIGHT: OR, THE ART OF ANGLING. Wherein are discovered many rare Secrets very necessary to be known by all that delight in that Recreation, both for catching the Fish, and dressing thereof by Thomas Barker, second edition 1659. If anyone gives it a try, let me know how it works.
1 Twelve pence, according to one of the introductory poems at the front of the book.
2 Possibly a pennyweight, a unit of weight equal to 24 grains, or roughly 1.6g. There are 20 to the Troy ounce.
The Reverend's Big Blog of Leather 
Excellent post! Thank you.
A Woodsrunner’s Diary.
I’ve tried something similar, minus the suet, based oddly enough on a blacksmith’s recommendation but no one had the proportions. Thanks for finding this, I look forward to trying it.
Interesting recipe. I tried this last weekend and 0.8g of rosin is not very much compared to the other ingredients. Maybe it is really ‘the amount of rosin you can buy with half a penny’, which is probably a little more. I used a small piece of violin rosin, it was about 15g.
Also, mutton suet is hard to get nowadays. Pig is more common and seems to do the same thing.
Also note that the book is English and UK measurements are different from US measurements.
I tried it on some leather and it works very well! I wonder how often you need to re-apply this to guarantee that it stays waterproof. All the best!
I agree that half a penny,s worth of rosin is more likely considering the other amounts, mutton suet was probably chosen due to its price and availability, beef suet being more costly,interestingly pig suet has a much lower flash and melting point,was freely available but not reccomended?.