Please note that I used Dritz brand grommets.  Since I have published the pattern, new brands have hit the market and not all 1" or 1 9/16" grommets are the same.  That number is the inside measurement, but the outer measurement may vary depending on the width of the grommet, the shape, etc.  The outer measurement of the Dritz 1 9/16" grommet is 2 3/8".  If your grommet is wider than that, please make adjustments to the size of the top band.