Where did you guys find plastic jars that fit the rings on the Critter? I tried U-Line but they did not know the fittings of the jars they sell. I thought the term Mason Jar would answer the Q, but did not.
I also don't like the idea of glass jars, and I like extras filled and ready to spray before I start the process.
Min, did you take the Critter apart, take off the jar base and put on the rings -lid of the plastic jars you found? Did not think of doing that.
If you take the gun assembly off the mason jar lid it can go on any size jar. I bought mine from Seattle Pottery Supply. They look just like the ones commercial pint glazes come in. (they are a lot lighter than glass jars too, makes it easier on the arm when you are spraying all day)
Just remove the mason lid (just a couple set screws) and use that as a template for drilling holes in the plastic jar lid. 2 for the set screws, one for the siphon tube and one for an air hole.