A first step into the nearly unknown: setting up, mixing dye with the soda/salt solution as explained by Helen Deigham, and some simple folding experiments as the example above shows.  All the fabric is dry pre-washed  white cotton.

More folding with elastic bands, both horizontal and criss cross to hold the fabric.  In spite of putting more dye into the solution, when washed the colour is no deeper.  However, the markings are attractive, the lower image reminiscent of mackerel skins.

One drainpipe was tied with elastic bands the second with raffia.  Even though the raffia did not grip the cloth so tightly when it was pushed together the markings are attractive and only a little less defined than with elastic bands.

When released from from the bindings and drainpipe the dyed cotton fabric is crisp and almost sculptural in quality -- a shame to wash it.  

Fabric fastened round drainpipe with elastic bands.

Fabric fastened round drainpipe with raffia.

Below are samples which have been pinched and tied with elastic bands (bottom left) or hand or machine stitched. As with all the previous samples the fabric was dry before adding the dye.

After the stitching was unpicked, but before washing.

The samples below are after washing and ironing. 

The fabric above was pinched and tied with elastic bands.

Handstitched cross-hatching.

Rolled and criss-crossed with elastic bands.

Looking back over three days of experimentation (these are just examples of what was produced) whilst the patterns produced are attractive I have not managed to achieve a good range of tones.  Not only does the dye appear blue, but in spite of making a fresh batch of dye each time and increasing the strength of dye used there is little difference in the results achieved..