This flat slip-stitch granny square join is the joining method I used on the Sunburst Granny Square Blanket (see picture below). It gives a flat yet clearly defined vertical and horizontal lines that frame up the squares.
[Update March 31, 2015: If you are interested in the solid granny square crochet pattern, please click here]
The method is similar to slip stitch join I did on the African Flower Purse, but instead of joining at the back of the squares, this flat slip-stitch method is working from the front of the squares.
There are plenty of joining methods for the granny square, choose the best to suit your project. Perhaps I should make a roundup to show you some of those popular and commonly use joining methods.
I hope this will come soon [Update : Click here to choose from the 12 ways to join your granny square]. Stay tuned! While waiting for that, please click page 2 for the detailed tutorial of this flap slip-stitch method.
Flat Slip Stitch
This is the joining method I used on the Sunburst Granny Square Blanket (see the last picture below). It gives a flat yet clearly defined vertical and horizontal lines that frame up the squares.
Place the squares with the right side showing up as we are going to work on the right side of the square. Make a slip knot on the hook to begin, insert the hook into the back-loop of the corner stitch of the first square, bring a loop out and make a slip-stitch.
Note: If your squares have 2 chains at the corner (like mine), pick the chain stitch just before your first double crochet stitch on the edge that you are going to join.
If you have more squares to join along the way, continue to do so until you reach the desired pieces of a granny square in the row. fasten off.
Repeat the same to complete all the row seaming for the whole project before you proceed to join the column (vertical lines).