Sunday, 14 October 2007

organic cotton - dipdyed re-visited

Since writing up my original findings on dip-dyeing organic cotton I have re-washed in Ecover and rinsed all the test samples. But I've struggled since to take good photos to illustrate the new findings... pixelation appears to distort evenness of dye, but at least colour variation can be seen - relevant for the eco-bleached white percale.

New comments are added at the end of this copy of my original findings: original comments are in blue italic.

hot water soak, hot wash with Ecover, boil with soda ash

As discovered in earlier tests, powerloom's wettability is its downfall. Following the (already proved inadequate for handpainting) scouring techniques of boiling with soda ash and soaking in hot water the fabric could be seen to have inconsistently absorbed both water at soaking stage and dye at dyeing stage – the boiled-with-soda surprisingly worse than the soaked only (not boiled for long enough?). A hot wash and soak with Ecover appeared to accept both water and later dye properly. After boiling out, drying and ironing, the same pattern emerges: the hot Ecover wash and soak is the most evenly dyed, let's give it 90%. The hot water soak gets about 65% and the boiled-with-soda about 50%. I'm sure trying an hour long soak in Ecovered water with more agitation (ie washing!) and rinsing would make up that final 10% to give very consistent dyeing.

The Ecover didn't make any difference though to wax removal – around 20 minutes boiling wasn't enough to shift it. The Ecover wash's waxed area feels as stiff as the previous tests but interestingly it doesn't have a darkened stain (from spread ironed-out wax) which I would have expected.

For me, powerloom isn't worth the bother of batikking on if the wax can't be removed easily, but it could be worth pursuing for dyeing only purposes – it's a pretty tough fabric that could have its uses.

The Ecover scoured sample's dyeing rating has risen to 95% following the final wash and rinse in Ecover but I still feel a longer scour in Ecover is worth pursuing (even if the fabric isn't conducive to wax removal).

direct, hot water soak, hot wash with Ecover, boil with soda ash

Being the dua donna of batik fabrics despite its name (primissima comes tops, I am told) I expected perfect results. Prima is my control fabric, despite being not organic (as far as I know), the one to compare all others to. It apparently is ready-prepared for batik – ready to take wax as well as dye. No scouring necessary.

Certainly there is no difference between different scouring techniques. On closer examination all versions show small streakiness consistent with the woven density of the fabric, not a problem but a feature of the fabric. At arm's length the colour appears even.

A couple of the samples show darker dye lines, one is on a crease. The second isn't but possibly is related to the production process though I couldn't say for sure. Nor why part of a crease has taken up more dye while (presumably) others didn't. Perhaps it was dye-bath related (not agitated there enough?), or hasn't been rinsed enough, or came about in the boiling out stage. Only further tests will enlighten, methinks.

The extra final wash in Ecover was enough to remove all traces of the darker lines!

Bishopston handloom
Fabrics handloom

direct, hot wash with Ecover, boil with soda ash

I expected these fabrics to take dye easily whichever scouring process (or none) was used, based on the handpainting results. And I'm not disappointed with the soda ash boiled or Ecover washed ones! If anything, the dipping has improved them. The inconsistency of weave is less obvious or at least regular enough to give a pleasing, vaguely streak "texture".

The direct (to pre-dye soak) versions though do show some unevenness in dyeing. Especially on the Fabrics handloom a straight line with "streaks" below it has paler dye – to be fair I can figure out this line continued on to the Ecover wash Fabrics handloom but only from looking deliberately for it! These lines must have come during the fabric production process as they are not thread/weave related (as the lines previously mentioned are). It may be that a longer soak in Ecover would have shifted them. They don't show in the soda ash boiled sample because it is from part of the fabric that didn't have that line running through it. Will any test ever cover everything that results throw up!

A few dark blemishes in both handlooms still show, but not so bad that I wouldn't wear clothing made with these cottons.

Following the extra final wash in Ecover any inconsistencies in dyeing are hardly apparent. The line mentioned is weave not dye related, revealed by a magnifier.

white percale
hot water soak, hot wash with Ecover, boil with soda ash

Being my favourite fabric so far, I expected these samples to dye beautifully enabling me to further praise this gorgeous percale. But I can't. Nor can I quite put my finger on why either. And then I look again and wonder what's the problem.

What should be top of the whole organic cotton experiment – ecovered hot washed white percale – has a few paler dye patches, akin to bad dyeing (ahem, also to fingermarked "something" preventing dyeing). Could it be I didn't rinse the Ecover out well enough? I'm more inclined to think the problem is a blip in my dyeing (but then might that not also apply to the handlooms?)

All samples have (non-related) dark straight lines one side originating probably from creases (prima also showed one or two of these). But most disconcerting is the impression of little bits of darker dye on mini-crumples right across the cloth, a kind of veining... perhaps they all need a really good wash and rinse. I will report back when this is done.

Big surprise from the final Ecover wash! All samples have lost colour, they are marginally but noticeably lighter than all other cottons. Before it wasn't possible to see any difference.

Whilst the aforementioned darker lines remain, the darker mini-rumples have been shed. Because of both this and the darker lines going in the prima, a further longer wash and rinse in Ecover suggest themselves!

natural percale
hot water soak, hot wash with Ecover, boil with soda ash

Natural percale is another fabric I knew would need scouring, according to previous experiments. Of the three scours tested little difference if any can be perceived in end result. They have a similar bit-of-excess-dye-on-the-surface look as white percale, whilst also having a not entirely even dye look. Again I find it hard to describe exactly what I see, mainly because I don't understand what has happened to make it this way. However, compared to the white percale, I don't see any dark crease dyemarks.

I will see if further washing and rinsing changes anything, and experiment with scouring to see if it's all down to some residue.

Wax wouldn't completely boil out again, despite length of time. Like powerloom, it may be this cloth isn't worth pursuing for batik. There again, that results (usually!) are more than good on white percale points to discovering the difference in production process – can it just be the eco-bleach process that enables the dye to (usually) be better absorbed (I should use the word "bonded") and is it just the lack of eco-bleach that prevents wax being boiled out properly?

There is no discernible change except possibly a reduction in dark mini-rumples. Like the white percale, it will be worth trying a longer wash in Ecover.

hot water soak, hot wash with Ecover, boil with soda ash

Close examination suggests the dye is patchy despite appearing even enough at arm's length. But this is probably due more to the uneven thread width and loose weave making denser thread areas seem pinker than others that allow more background to show through. There seems no difference between scouring methods.

Examining the cloth through a magnifier shows the cloth is (and probably was?) evenly dyed, it is indeed thread width inconsistency suggesting minor variation. The extra wash in Ecover made no discernible difference to dye quality.

nettle mix
hot water soak, hot wash with Ecover

It's the first time I've dyed with this fabric, because of having only a small sample (less than A4). The fabric is slightly stretchy and dense, so more suited to clothing than paintings. It frays easily...

Both samples dyed beautifully evenly though wax was hard to shift and some remains in the fabric. It's hard to say much more without more fabric to look at and understanding gleaned from other tests

Umm... no change, or rather I can't think of anything to say!

No comments: