Techniques used for engraving Aegean seals
Will you speak to me about techniques?
Yes, what do you want to know?
Yes! As I said in the previous lesson, soft stone seals can be engraved by hand tools. These are, for example, the knife, the burin, the chisel and handheld drills! The tools are presented on the surface of the seal and are manipulated by hand to engrave the intaglio.
Ok, got it!
But wait, there are also the hard stones. These stones are so hard that it is impossible to simply engrave them by hand tools. If you want to cut them you need two things: fast rotation of your tools as well as a paste consisting from powder of very hard stone and a binder.
Hmmm.... I am not sure I understand how this works...
Well, there is not much information about the Aegean Bronze Age. However, a second century AD burial stele of the eighteen years old seal engraver Doros from Sardeis gives us the answer! A tool we call horizontal spindle bore a horizontal rod that could rotate in itself. Points of various shapes would be attached at one end of this rod. A bow wound around the rod would be used to rotate it. The fast rotary motion would allow the points on the rod to cut through the hard surfaces presented to them!
And what about the abrasive powder you mentioned before?
Well, fast rotation alone does not suffice to cut hard stones. You also need a powdered material of hardness greater than the stones, this is what actually does the cutting! This could have been powdered emery, a stone of great hardness whose tiny particles would actieve the cutting of the stone.
The bow is moved back and forth, this rotates the rod and your cutting tools, that is the points at its end. You take some emery powder mixed with a binder, say some oil that binds the powder into a paste, and put it at your points! You present your stone to the rotating points and the emery cuts through it!
Ok, I now understand... But in the video you just linked for me the tools are presented to the stone and not the opposite...
Yes, ok, these are modern tools you see here, in antiquity it was different, the tools were attached on the fixed spindle!
Ok... And where did they find emery in the prehistoric Aegean?
It is available in Naxos at the Cyclades!
Yes, I see... I think I now know all about techniques now! Ciao!
Oh no... I only spoke to you about engraving! But there are also cases of seals that are not engraved but cast or also pressed in a model! It is rarer but we have for example signet rings with cast bezels and glass seals that were made by pressing glass in a model that had an engraved motif in relief. This would then appear in negative in the glass seal! And in some cases you even have seals dressed in gold foil, which was pressed in an already engraved intaglio! And...
Oh no, Genius, enough, I got it! You also have some other techniques, but since they are not that common can I go now?
Yes, yes... See you next time!