Aida cloth is favored by cross-stitchers for its construction which aids in the counting of stitches. It comes in a variety of thread counts, also known as the number of holes per inch of fabric.
The different types of Aida cloth are labeled according to their thread count. Therefore, 14 Aida cloth is a 14-count fabric which gives 14 stitches per inch, and 18 Aida cloth gives 18 stitches per inch, since it is an 18-count fabric.
The thread count determines the size of the stitches and therefore, the size of the design as well. According to the Cross Stitch Centre, "the finer the fabric used, the smaller the stitches become." For a smaller design, use 18 Aida; for a bigger design, use 14 Aida. The advantage that 18 Aida has over 14 Aids is that it makes the completed stitching look more fine and detailed. The holes are closer together on the higher fabric thread count, which is 18 Aida.
Aida cloth is made up of groups of threads which are woven together, and the holes are clearly defined at intersections. This helps make stitching easy and accurate. Choose the type of Aida cloth according to how big you want your completed design to be.