Each strip of metal has a thickness of 19 microns which is only about a third of the diameter of a human hair! You can easily understand that these precious metal threads were extremely expensive; the use of them in such large quantities in Henry’s tapestries shows just how valuable and glorious they were.
The period between the late 15th and 17th centuries saw the development of the technique of cast, drawn and rolled metal threads. A gilded cast silver or silver alloy rod was drawn through holes of decreasing diameter and the resulting wire flattened between rollers and wrapped around the silk core. This was dyed according to the colour of the metal; yellow or red for gold threads, undyed white silk for silver.
Over the centuries, the metal threads in the Abraham tapestries have corroded which is why they appear a dark grey colour today.
Microscopic view of 16th-century triple-wrapped metal thread.
To find out more about how tapestries have been cared for over the years, click here.