With this style of shaker card though, you skip the foam tape and bulk. Instead, wrap clear mylar, acetate, packaging, report covers, cellophane, basically anything you can find that’s clear, around the area you want to shake. You could make the entire card a shaker if you wanted to! Obviously the thicker the material you use, the better your card will hold up.
I grabbed one of my husband’s clear comic book bags and cut a piece that would fit around my panel. Then I added the shaker elements to my panel, folded the sides of the clear mylar back behind the panel, and secured all the sides with tape. I like that the snowflakes move around plenty when you shake it, but it also tends to hold the shaker contents in place. It’s a good balance. Love how the snowflakes float around the darling snowman like it’s really snowing.