Birthday plaids are made so that the vertical and horizontal stripes reflect the name and birthdate of a person. They make unique gifts, especially for a baby. I especially like them as baby presents because they must be finished after the baby is born.
Numbers are stitched with stripes the width of each digit. Letters are converted into numbers. You can pick the colors you like, they are always charming.
My most recent plaid is pictured above, and below, you will see some other examples of birthday plaids.