Entrelac, or interlaced, needlework is a method of working yarn into squares of fabric that appear to be woven together like the slats of a basket. Knitted entrelac works individual sections of an ordinary cast-on row, then works new sections against those squares. This can be frustrating on a rigid knitting needle. It's less awkward worked in Tunisian crochet, also known as afghan stitch. Even though the tool used is a cross between a knitting needle and a crochet hook, you can work just one square at a time and let the rest dangle.
Chain 31 in one colour. Insert your hook in the second chain from the hook, draw up a loop and keep it on the hook. Draw up loops from the next three chains, so you have five loops on your hook.
Draw up a loop from the next chain and pull it through the first loop on the hook. Reach again through this new loop to catch the yarn and draw it through the first two loops on the hook. Repeat until you're back to the starting end and have just one loop on the hook.
Insert your hook under the vertical of the row before. Draw up a loop and keep it on the hook. Draw up loops from the remaining stitches for a new total of five loops on the hook.
Repeat Step 2 to complete the second row. Make three more rows in this fashion for a total of five rows in a square.
"Bind off" the top of the square with slip stitches. Insert the hook under the vertical as in Step 3, but draw the loop through the stitch on the hook. Work slip stitches on back to the foundation chain. The first square will be like a diamond threaded on the chain.
Start the second square in the next five stitches of the foundation chain and catch an additional chain stitch as you begin to work the loops off the hook. Bind off this square as before. Work one more square to finish the foundation chain. Fasten off the yarn.
Attach the second colour of yarn to the top corner of the first square of the first tier. Work down the bound-off side of that square to the foundation chain, drawing up five loops onto the hook.
Insert your hook under the vertical of the first row of the second square. Draw up a loop and work back through the loops on the hook.
Work four more rows until this first square of the second tier fills the space between the squares of the first tier. Bind off with slip stitches across the top of the square. Work another square in the second colour between the other two squares of the first tier and fasten off.
Attach the first colour or a third colour at the same corner where you started the second tier. Chain six. Work the first square as you did the first square of the first tier, but draw up loops from the side of the second-tier square to begin to work off the loops.
Work the second square of this tier as you did the squares of the second tier.
Begin the last square of this tier by drawing up five loops from the bind-off slip stitches of the second-tier square. Yarn over and draw through only one loop to begin to work off each row. Bind off both free sides of the square, making a slip stitch, single crochet and another slip stitch in the corner.