Begin by bringing the needle up through a hole of canvas, and take it back down through the same hole, leaving a loose loop on the front of the canvas.

Next, bring the needle up two canvas threads below the first part of the stitch and through the loose loop left on the canvas. Now the thread can be pulled tight.

Repeat the stitch by taking the needle back down through the same hole it has just come up (through the first loop)

and out again two threads below.
Continue the sequence.

At the end of the row make a small stitch over one canvas thread to hold the final loop in place.

The second row of chain should be worked one thread across from the first.