The yarn is 2 strands held together - one of KnitPicks Crayon cotton, and the other KnitPicks Peruvian Highland Wool. The resulting fabric feels fabulous and has a great weight and drape. I bought the "Bare" version of these yarns - not only are they ready for dyeing that way, but they come in larger skeins (fewer knots). I knit each of the rectangles in basic stockinette, throwing in an occasional purl row to suggest ripples in the water. Not the most exciting project to knit, but more portable than knitting a blanket in one piece.
After all nine rectangles were complete I mixed up the dyes. I used acid dyes, specifically counting on the cotton strand to NOT take the dye the way the wool would. The result, so I hoped, would be a heathery look with the boucle cotton providing a hint of frothiness or sparkle on the water. I hand-mixed several shades of blue-grey-green, then added touches of bright yellow to suggest sunlight. I practiced several methods of applying dye on a swatch, and settled on using a sponge to pat it on the presoaked rectangles. Then I rolled them in plastic wrap and steamed them. I am really pleased with the result. Each "pane" is different, maintaining the abstract feel.
The next step was to pick up stitches along the edges and knit the pieces together. Then I picked up stitches all the way around and knit the border with mitered corners. I don't think I ever counted the total number of stitches around the thing, but it was A LOT. I had to link together about 5 or 6 Options cables, and broke several in the process due to the weight. To create a neat stretchy edging I bound off with a mile or so of applied I-cord. It wasn't until I got the thing off the needles that I could see that it turned out about 40% larger than I planned. The original lap-blanket-for-two ended up large enough to almost cover a queen size bed!