Thursday, 9 August 2007

organic cotton testing 2

Today I painted the organic cottons with basic Procion colours (cyan, magenta, yellow, black, as I call them, showing my graphics background). As a reminder, the test fabrics have been only soaked for 30 mins in water, rinsed twice then drip dried. None were heavily creased from this, in fact, while painting I wondered if I was working on straight from the roll fabric!

There were a few surprises, which weren't so surprising after I'd thought about them... the white eco-bleached percale took dye very close to acceptably but the natural percale didn't. Something in the eco-bleaching must have made the fibres more receptive to dye – though the final analysis won't come until after boiling out the wax. Both percales were gorgeously smooth to wax on, just like prima, and despite their expense which I daren't check back on at the moment are currently top of the list. The two handlooms took dye easily, which doesn't surprise me, but what I can't figure out is whether they have been prepared for dyeing or not – instinct suggests not, because the weave is so haphazard and price low. It warrants investigation, because if the chemical treatment given to other cotton to make it super regular also prevents dyeing then... well something to ponder once known!

1 Greenfibres soft voile
waxing – smooth enough to work on but waxing lines look pixelated because of looseness of weave. Meaning some lines may not be thick enough to withhold dye.
soda ash fix application – very slow and unspreading, may not be consistent.
hand-painting dye – no spreading at all, but seems to have absorbed through.

2 Greenfibres natural percale
waxing – beautifully smooth and even lines.
soda ash fix solution – slow, eventually soaking through.
hand-painting dye – virtually no spreading and not completely through at once or when dry.

3 Greenfibres eco-bleached white percale
waxing – very smooth! fantastic for waxing.
soda ash fix application – just about OK, soaked through but not immediately.
hand-painting dye – spreads slowly, and slowly through.

4 Bishopston handloom

waxing – penetrates cloth fantastically but the uneven texture was apparent, drawing the canting was a little rough.
soda ash fix application – fine, no problem.
hand-painting dye – easily spreads and penetrates.

5 Fabrics Ltd powerloom
waxing – it wasn't too bad for waxing as regards smoothness of surface but penetration problems came once the wax started cooling.
soda ash fix application – a joke! No penetration!
hand-painting dye – seemingly no absorption at all, dye not penetrating at all. Cloth is definitely coated with something that needs removing.

6 Fabrics Ltd handloom
waxing – penetrates well, seems a little smoother for drawing than Bishopston's handloom.
soda ash fix solution application – fine, no problem.
hand-painting dye – easily spreads and is absorbed.

7 Textile Techniques prima
waxing – absolutely lovely to work on but seemingly not quite as smooth as percale!
soda ash fix solution application – fine
hand-painting dye – smooth, very fast absorption and spread.

Summary: Dye was absorbed fine on prima, white percale, and seemingly Bishopston handloom. Dye wasn't fully absorbed to the reverse side on Fabrics handloom, voile and natural percale, though it was marginal on the handloom. On powerloom it had hardly penetrated to the reverse side.

Hence powerloom requires a serious attempt at scouring. To compare results I will do equivalent tests on all other fabrics. I see two levels of scouring – boiling in water with soda ash and soaking in warm water with soda ash. The powerloom is so heavily opposed to receiving dye my inclination is to start with boiling and if that works try again with warm water. If boiling doesn't work... well, I'll decide then!

The other reason for starting with boiling is that I need to boil out the wax to test fastness of dye on tests already done, so can boil other cloth at same time (not ideal to do it in waxy/dyey water but good enough!).

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