Rather than putting a plate on top in the microwave, I have resorted to using a lightly dampened paper towel, gets the job done just as well and one less dish for me to clean.

Now I’m curious about the wet-strength resins in paper towels. Are they safe?

FWIW the USDA says plain paper towels are fine to wrap food while microwaving [1]. But I agree with the notion of wanting to minimize exposing food to toxins. I try to limit my microwave usage all together and prefer the oven for reheating food.

[1] https://www.fsis.usda.gov/food-safety/safe-food-handling-and...

There's plenty of places that sell glass dishes with glass lids. I hadn't even heard that plastic lids were thing until I read your post so had a look on Amazon and even on there it seemed to be ~50/50 mix of plastic and glass lids.

You don't need to go vintage either. The Pyrex dish I bought around 5 years ago, to replace another Pyrex dish that I accidentally dropped, came with a glass lid. And the set it was replacing, which was maybe around 10 to 15 years old, had glass lids too.

As for being microwave safe, I thought the whole point of Pyrex dishes were that they could be thrown in the oven, microwave, under a grill and pretty much everywhere? Or does this vintage set have visible signs of age, which makes you concerned?

Why not use a paper towel?

> but she doesn't trust they're microwave safe.

The glass or the printing? Mine have survived without issue.

Remove the lid before heating.

What's the problem with the plastic lid in the microwave? As long as it doesn't touch the food shouldn't you be perfectly fine?

Water accumulates oh the lid (steam), then eventually drips off into the food with all the microwaved-plastic goodies.