Before you start, position your pieces so the right sides are facing upwards and the edges are together, lined up stitch by stitch. Thread your needle with a length of matching yarn.

Insert your needle through the two edge strands on your piece, going from back to front, leaving a tail which you will weave in later.

Take your needle through the two edge strands on the secnond piece, which correspond with the two on ther first piece, again you take the needle from the back to the front.

Now, take your needle under the next 2 strands on your first piece.

Then under the next 2 strands on the second piece.

Continue repeating steps 4 and 5 along the edge to join your two pieces.