Nancy! Looks great! :)
I made one just like yours recently - it turned out alright, but I think I used too small of a box. Cardboard was getting into my shots, so I had to zoom (I prefer not to, so my background stays fuzzy & my product is sharp) or get too close (aaaand then my camera can't focus).
I am planning on trying one like this next:
http://shrimpsaladcircus.blogspot.com.au/2010/03/how-to-sday-10-dollar-10-minute-fold-up.htmlIn the meantime, my kitchen counter is doing the job alright. I over expose, but it hasn't really been a big deal. It's flattering (I'd say) and blows out things (like my street in the background) that would detract from the image anyway.
Sorry for the long reply! I'm glad you've found a great photography solution!