The making of gold leaf in those bygone days was an art form in itself.
The gold was first rolled out into a flat ribbon, then cut into small squares, which when piled up alternately with pieces of goldbearer's (perhaps, goldbeater's) skin*. (Of which, more later.) The pile was placed on a solid stone anvil (selected to lessen the incidence of impurities), and beaten with a series of heavy hammers. First one of sixteen pounds, then eight and so on until the small squares of gold extended beyond the edges of the skins. (Note that the typical sledge hammer so popular with the do-it-your-self woodsman is in the range of 8 pounds to 10 pounds.)
The gold squares now in an irregular shape are removed, cut into quarters, trimmed, repiled, hammered again until the gold once again extended beyond the edges of the skins. Again the squares are trimmed, cut into quarters and the process repeated until the gold reached the desired thickness. A workman would spend three days reducing fifty pennyweight of gold into leaf. (Note: A pennyweight is one twentieth of a pound (i.e., one troy ounce). So the workman reduced his two and one half pounds of gold into leaf in one week.)
The sheets are then placed in books which are three and three-eights inches square, with twenty five leaves to the book And the books are formed into a pack containing twenty books.
Some quarter of a million sheets (or leaves if you prefer) go into a pile that is only one inch high. Actual number is 254,248 leaves.
But wait there is more, if desired, the sheets could have been hammered at least once more to yield an incredible half million sheets. � One continuing use of gold leaf in addition to the art world, is to coat food. Why, you may ask? Because it's pretty, a fantastic decoration, and actually not that expensive. You can have a gold clad strawberry in you champagne for your wedding reception or other festive event. That's one up on the Jones, or whoever. Gold in this form is of course indigestible, but the quantity is so insignificant that it is of no consequence. An article appeared in Wall Street Journal several years ago on this subject.
As might be expected, gold foil is much thicker than gold leaf and is used for such mundane things as fillings of teeth, &c. There is a tradeoff between cost of the gold vs. cost of processing.
Actually gold is relatively inexpensive, and destined to become more so as mining technology permits chemical extraction from gold bearing materials which until recently were considered uneconomic. And as countries, as example, England, United States, Russia sell their gold hoards the supply of gold will far exceed consumption.
It appears that gold has always attracted the huckster. One common device used by traders of old was to use a purse for their gold coins. The purse was lined with pumice and in the day-to-day traffic of business the coins in the purse were only slightly abraded and the damage was not obvious to the undiscerning. After a period of time, the purse was cleaned and the gold powder recovered. Just another way for a business man to make a buck?
For more on gold foil, thread and leaf refer to one of the older encyclopedias which give wonderfully descriptive essays on the subject. As example, "The Standard Reference Work" Chicago Progressive Educational Society, 1913.
.*Producing Goldbearer's (perhaps goldbeater's) skin was an art in itself. Imagine that it had to be free of any foreign matter, tough yet firm, supple, thin, and reusable. Having a ready source would also be important. A biologist would argue that the source is truly a skin, however, we would perhaps make another judgement. The best source was the large intestine of cattle. Properly prepared the skin having been well tanned, was so smooth that the gold would not adhere to it. We now know that smoothness was only one of the required features. The skin actually was permeable to air, so that there was no vacuum formed between the leaf and the skin. (When one uses the leaf to coat items even today, advantage is taken of the fact that the leaf encompasses the item being coated in such a way that the air is excluded and the leaf is held in place by atmospheric pressure and the formation of a space (if it existed) devoid of air.)
� ***