Aida is the brand name of a popular fabric used for cross-stitching. Aida fabric is woven to have a certain number of holes per linear inch through which cross-stitch floss is sewn. Aida fabric comes in a variety of sizes, from six holes per inch to 24 holes per stitch. Aida cloth also comes in a range of colours, and can be bought in different lengths and widths. Cross-stitch patterns generally recommend the size of Aida to use to accomplish the project.
Lay out your Aida cloth so that it is flat on a table or other firm surface. Weigh down the corners to keep it from slipping.
Select a portion of the cloth toward the centre, where the vertical and horizontal fibres of the cloth are straight and not unravelling or warped.
Place your ruler on the cloth with the mark for 0 at the leftmost edge of a hole. Lay the ruler flat along a horizontal line of the cloth. Count the number of holes between the 0 and the 1-inch mark on the ruler. The number of holes in that range is the size count of your Aida cloth.