Silk

Spring is most definitely here – we have had a couple of warm days, the flowers have burst out and the days are noticeably longer. With spring comes a desire for lighter knits, and not necessarily in wool. As you all probably know by now, I would remind everyone that wool has thermodynamic properties, so it is fine to wear it in warmer weather, but I have to accept that not everyone wants to do this, and so have been bringing in some different fibres for summer knits. Some of those fibres contain silk.

Silk is a wonderful, luxurious fibre. It has a long history, originating in China as far back as the Neolithic period. China maintained a virtual monopoly on silk production for nearly two thousand years, although people outside China were able to buy silk via the Silk Road which was established around the first century BCE. The earliest surviving silk fabric dates back to 3630 BCE. According to legend, the development of silk was due to the Chinese empress Leizu and silks were originally reserved for the emperors of China for their own use and for gifts. It was also used as a surface for writing. As it spread outside China, silk became a very popular luxury fabric and was a staple of preindustrial international trade. We know that the Romans purchased silk, although it was considered to be very decadent and effeminate to the point that the Emperor Tiberius passed sumptuary laws forbidding men to wear silk (apparently this was ineffectual). Similarly in Islamic teachings, Muslim men are forbidden to wear silk. The reason is not clear, but seems to be similar to that of the Romans, that silk was considered too feminine and extravagant.

Once China’s monopoly was broken, other places became major producers of silk, notably India, Thailand, and Italy. In France, the centre of the silk industry was Lyons – I am hoping to visit when I am in France in June. King James I attempted to establish silk production in England, purchasing and planting 100,000 mulberry trees, some near Hampton Court Palace, but it turned out that they were unsuited to silk worms so the enterprise was a failure. There were some silk throwing factories in the UK and some British silk production based in Cyprus, but overall the UK has not specialised in silk, focussing instead on wool and cotton.

Commercial silks come from reared silkwork pupae, bred to produce a white coloured silk thread with no minerals on the surface. The pupae are killed by either dipping them in boiling water before the adult moths emerge, or by piercing them with a needle. This enables the whole cocoon to be unravelled as one continuous thread, permitting a much stronger cloth to be woven from the silk, and producing a fibre which is very easy to dye.

Alternatively you can get wild silk, produced by caterpillars other than the mulberry silkworm, but the scale of production has always been much smaller. This is because the caterpillars differ from domesticated varieties in colour and texture and are therefore less uniform. In addition, cocoons gathered from the wild have usually had the pupa emerge from them before being discovered, so the silk thread that makes up the cocoon has been torn into shorter lengths. Finally, many wild cocoons are covered in a mineral layer that prevents them from being reeled into long strands of silk, making the processing of the silk tedious and labour intensive. The fabric is not as smooth or shiny (see below). It is also more difficult to dye. Africa and South America are big producers of wild silk.

There is also spiders silk – used in the ancient world as wound dressings as it has antibacterial properties. I am not sure that anyone has used it commercially, although I would not be surprised if someone somewhere had not used it for a fabric of some sort.

I had silk worms when I was a child in South Africa, keeping them in shoe boxes and lovingly feeding them mulberry leaves from the tree in my parents’ garden. My mother found the moths irritating as they would hatch and lay eggs all over the place. But it was fascinating to watch the whole process from egg to moth. For this reason, I have always been a bit squeamish about commercial silk, lovely as it is, and prefer wild silk where possible. I am pleased to be able to stock Knitting for Olive’s Pure Silk, which is a bourette silk, spun from cocoons from which the pupae have already hatched. We also have some yarns which are blended with silk, such as a range of mohair silk blends (from Knitting for Olive, Lang and Hjertegarn as well as my own hand dyed mohair silk. We also sell Organic Trio from Hjertegarn (wool, silk and cotton – all organic) and Silkpaca from Malabrigo, a blend of alpaca and silk. And, unrelated to knitting, we also have silk embroidery threads from the French company Au Vers a Soie, which are truly gorgeous.

As always, when I start writing these blogs, I realise that there is a whole world of history, geography and economics behind one apparently simple fibre. I wish I had more time to go into it.