I globbed mine down the length of this rulers edge kind of thick. I Googled the length of time it takes for the Elmer’s rubber cement glue to cure and it said about 20 minutes but I waited an hour. It still feels tacky to your fingertip even when dry. The tackiness decreases as it picks up fuzz off the quilt surface and I think eventually it will need to be replaced but so far mine is still working. Try your ruler on a scrap piece of fabric and check for any transfer of the rubber cement. If no transfer, it’s dry enough.