Pattern transfer: enigma of the silverpoint

As part of my research into medieval goldwork embroidery, I read many collection and exhibition catalogues. Most are written by art historians and only a small proportion by, or with the help of, textile curators/conservators. Most texts are therefore only partly useful to the embroiderer. The gold-standard, in my opinion, are the books published by the Abegg-Stiftung. One of the aspects of medieval embroidery that particularly interests me is the pattern transfer. As far as I know, there has never been a systematic review of the substances found on these textiles that result from the initial pattern transfer onto the fabric. More recently, detailed chemical analysis did take place for some of these medieval embroideries (for instance the vestments from Bamberg, soon to be published). More commonly, you will find vague references in these catalogues to the materials used for pattern transfer. Either ink or paint. But last week, I came across the silverpoint.

The silverpoint consists of a piece of pure silver mounted on a handle. You can buy them from well-sorted art supply shops. Silverpoints were used by medieval scribes and have been used by some artists till the present day. Silverpoints are the predecessors of our modern lead pencil. But contrary to a lead pencil, the silverpoint will not work on normal paper. The paper, or for that matter vellum, needs to be prepared with chalk and/or egg yolk (or similar products). The chalk makes the surface rough so that small particles of silver are shaved off the silverpoint and the egg yolk contains sulfur that oxidises these particles so they turn from faintly visible grey to dark brown or black. The air oxidises the silver particles too, but the egg yolk seems to speed up the process.

The silverpoint intrigued me and I wondered if it could indeed be used to transfer a pattern onto fabric. Linen is a little raw, so I hoped that I could just scribble onto it. Nope. No lines visible. No further oxidation on the air after a few hours or even days. And I am not at all keen to go the sulfur (egg yolk) road. Because the sulfur will also tarnish my goldthreads as a large part of their composition is silver too. Does this mean the silverpoint could not be used for pattern transfer? Or does it mean that I need to prep my linen in a different way? Any ideas more than welcome!

I read about the silverpoint in the catalogue on the collection of the Schnütgen Museum in Cologne. It was published nearly 20 years ago by Dr Gudrun Sporbeck, an art historian. Apparently, the body of Christ on a chasuble cross with inventory number P223 is drawn with a silverpoint onto the linen. Did she determine this? Or did she copy from the older literature stated? The older literature in which this particular chasuble cross has been described dates from 1888 till 1938. Was it just something that was assumed? Did somebody do some chemical analyses? Only one way to find out: ask her. So that's what I am going to do. Will keep you posted.

Update: I contacted Dr Gudrun Sporbeck repeatedly, but never received an answer. In addition, Enikö Sipos also experimented with the silverpoint on textile and came to the same result as I have: it doesn't work.

Literature
Sipos, E., 2005. Proportions and measurements. The making of the chasuble. In: Kovacs, T. (ed.), The Coronation Mantle of the Hungarian Kings, Hungarian National Museum: Budapest, p. 91-107.
Sporbeck, G., 2001. Die liturgischen Gewänder 11. bis 19. Jahrhundert (=Sammlungen des Museum Schnütgen Band 4), Museum Schnütgen: Köln.