If you've got seal issues make sure it's not the lid first. If it's a desktop, hold the lid up a few inches and let it drop. It should not slam or slap closed but rather ease down in the final 1/8th inch like there's a bit of air being pressed out. Also, there's a 'dollar bill test' where you would try and fit a dollar in between the lid seal while closed. If you can slide a bill in between the wood of the lid and body you may have issues at that point.
Glass is known to leak though...This is what I used in a recent build.