pic: Seattle Cascade tubes.

[SamMullen]

My brother and a friend of ours inflated the first 60 or so tubes for the Olympic field and they said they pumped it up till it looked right and then they popped the u shaped stencil thing on the tube, making sure both sides were touched. They let off a little air if the tubes were compressed, but they also said they didn't have to do that. They said the way it was explained to them it was only illegal if it was too small to touch both sides, not if it was really large.