Homebrew PCBs

>I use glass Mason canning jars. They come with a lid and ring but you 
>can buy plastic screw on lids. Has worked for me for 2 years.

     I'd suggest not using glass that seals. The hydrogen peroxide will 
continue to decompose and produce oxygen gas while in storage, which can 
produce enough pressure to burst the container (the type of seal on a 
mason jar with the two-part lid might be ok for this, but I wouldn't use 
it). I've had several exploding glass containers of other things over the 
years, and even if the contents isn't nasty the glass can fly quite a 
ways.

     I've stored the stuff in a brown plastic peroxide bottle, having 
squeezed it quite a bit before capping, and had it develop enough 
pressure to show stretch lines down the sides of the bottle. The big 
plastic ketchup squeeze bottles sound about perfect, since they can vent 
the pressure while sealed. The vented gasses will still rust/corrode any 
metal nearby...

     -Gary