We do not microwave cook in them, as that is not recommended, but we do microwave warm.
Mom is 94 and we have tried glass food containers,,,"too heavy". The lime,food preserve, green plastic containers,,,"i can't see what food is in there". Maybe i can use them? And the EasyFindLid line,"no". A whole big bag of those to give away,,, Or the Rubbermaid,Lock-it line with 4-fold down lids ,,,"i can't open these or close these, thanks anyway". She still loves to cook. Returned the Lock-it line for refund.
This has taken months, years, many brands and many styles. i have a full grocery bag of Ziplock store-bought light plastic food containers to give away,,,"i can't open this,,,anymore",,, (and doesn't close it completely either).
As i said , we use Pyrex covered bowls in various sizes to microwave COOK in, so have not had any problems yet with cracking in the Premier line. They do hold a lot of water in the "top rack-only" of the finished dishwasher cycle. Don't think i would buy the black rubber version if i had the choice of red or black rubber lid rims.
Also found a store back East ,,,everythingrubbermaidstore.com,,,( or something close to that),,, that ships individual large Rubbermaid- Premier line food containers,,, and larger sets than the 12 piece only set sold on Rubbermaid website. Not cheap shipping. But an option. Very hard to find in stores like suggested "try Target or Walmart or ,,,bla bla bla".
Thank you, Rubbermaid !!
