You've most likely seen brass grommets used on banners. Did you know they can also be used for foam core boards? We often are asked, "What size grommets work for foam core boards?"
A standard size brass grommet is designed for thinner materials like the vinyl banners. This size grommet when sealed/crimped will crush and dent your foam core, creating a nasty looking finish. This is where the XL size designation comes in.
The XL means you will get a longer barrel on the grommet, the portion that punches through your boards - also referred to as the LUF or 'length under flange.' It allows for safe use of grommets without any damage to 3/16 inch thick foam core boards. You just have to be sure to back off the depth adjustment on your grommet press - this may take some trial and error tests to set it just right, so it's best to plan on having some scrap board on hand.
The XL grommets are only available in the brass #1 diameter which gives you a 5/16 inch center opening, plenty of room for thin rope, cord, line wire or banner bungees to hang your signs.
Do you have questions about grommets or foamcore boards? Please ask them in the comments below.
