Monday, 23 August 2010

Weld I Never!

‘Tis the height of summer here in the North East of England, although nobody told the weather. That means weld is easy to spot if it is in its second year and throwing up flower spikes. This year has been good with large stands popping up allowing me to harvest decent quantities while still only taking a small fraction of each population leaving plenty of plants to generate the next generation. While I am happy to use dried weld it lacks the potency of fresh material
This has also proved ideal as I am currently dyeing like mad to stock up for the St Abbs August festival where we will be running a stall. The festival organised by Louise at Woolfish normally occurs in February and November but this year a third date has been added. Hopefully the summer date will also allow some fleece animals to come along as they have been absent the last two times due to the foul winter.
Weld is a traditional yellow dye but stands out from its contempories due to its excellent fastness, especially when used with alum-mordanted fibre. Unlike many other dyes it also doesn’t need high temperatures to bind and fix to the yarn making it suitable for solar dyeing. However I was not ready for the dyeing potency I encountered when I tried to dye alum-mordated, superwash-wool in a weld bath. Now superwash does suck up the colour better than normal wool but the reaction I saw was amazing in that the yarn went yellow after a minute in the dyebath, coresponding to a reduction in colour in the bath.

Yarn after a few seconds in pot.

This has now happened three times for me with different weld baths. All gave a vivid yellow without alkali treatment and using down to 70% weight of weld to fibre. The first time I rinsed then simmered the wool that was fluorescent yellow in plain water to ensure it was fixed and while there was some yellowing in the simmered water the vivid yellow remained on the yarn indicating wash fastness. Later batches are to be overdyed so I feel they will get a simmer then. This effect is restricted to superwash wool and hasn’t occurred with other dyes so might just be an eample of why weld is such a brilliant (no pun intended) plant dye.

The end result