Afghan squares are a good project because they are small and quick. The size of one afghan square typcially ranges from six inches by six inches to twelve inches by twelve inches. This makes afghan squares the perfect size project to bring with you, and each square is light enough that the process of crocheting one will not overheat you.
Types of Afghan Squares
The most well known afghan square is the granny sqaure. Granny squares are made by crocheting rounds in certain patterns, while squaring off the corners. Granny squares tend to be looked down on as guady or novice patterns, but there is such a variety of ways to do them that they do not have to be ugly.
Motifs are another popular afghan square. Motifs are specific designs, such as flowers, that are crocheted into the center of a sqaure or circle. They can range from very simple to very complex, depending on what type of design you'd like to use.
Some afghan squares are not even necessarily squares. There are several afghans that use rectangles, circles or hexagons to piece together blankets. These shapes work exactly the same way as squares, though the actual joining of the pieces may be more complex.
Yarn Weights
Any weight of yarn can be used for afghan squares, but the most popular is worsted weight. Changing the yarn weight will change how many rows or rounds you need to make the sqaure the same dimensions, because different weight yarns have different guages.
Joining Afghan Squares
There are many different ways to join afghan sqaures to make a blanket. Some are invisible, like the mattress stitch, and others create a texture, like single crocheting squares together. The join used will depend on the desired look and feel of the finished afghan.
The mattress stitch is usually used in knitting, but can work for crochet as well. It is performed by running the needle through the back of the stitch on one square from the back to the front, then running the needle through the back of the corresponding stitch on the other square, also from the back to the front. This creates a seam that is invisible from the front, because the join is being working through the backs of the stitches.
Squares can also be crocheted together using any crochet stitch, though single crochet is used most often. There is no difference between a normal single crochet and a single crochet join, other than the fact that the join requires working through two layers of stitches rather than one. Using this join will create a raised border around each square.
Some free afghan square patterns can be found at Crochet Pattern Central.