RAS Tempera Paint Questions (Used in Home Art Studio)

[cottonmama]

I am looking at the prices at Jerry's Artarama and am seeing that for $2 more than I would pay for a set of RAS paints (2oz per color) for each of my two kids, I could get the 16oz bottles of each color individually.  But I am reading on teacher forums that tempera paints (sometimes?) have problems going bad in a matter of months.  Supposedly you can add antibacterial soap or vinegar to help, but I don't know how much time that would buy me.

 

Has anyone bought in bulk or kept these paints long-term?  Or would the 2oz bottles be enough for two kids' use?

[pitterpatter]

Oh, really? I didn't know this. We bought a bunch of pre-mixed tempera at Michael's when it was on sale almost two years ago. None of ours has gone bad.

[Guest excited]

I'm definitely not an expert on art supplies, but our RAS paint has lasted a long time  I moved all our art supplies outside to our back porch (which, turns out, is supposed to be horrible for paint) and our washable tempra paint from Lakeshore Learning quickly went bad.  I had to throw it all away.  However, almost a year later, our RAS paint is still great - often kept outside and everything - and we use it all the time! I'll be making another purchase soon :)! 

[amiesmom]

I bought the 16 oz bottles of RAS paint a year a go and it is still just as good as it was the first time we opened the bottle.  I'm wondering if, and I could be wrong, but I thought tempera paint used to be made with eggs or something, so maybe that's where the 'going bad' idea comes from, but I don't think they make it that way anymore.