In general, paper that is lined with plastic should always go in the trash. Frozen food boxes are sprayed with a polycoat to protect from freezer burn. if it comes out of the freezer, it should go in the trash.Coffee cups and soda cups are also lined with plastic inside to protect the liquid from leaking out. Unless specially marked as compostable in which case you can compost them, then they should go in the trash.Take out food container such as salad bar containers, soup containers and Chinese food containers are lined with plastic on the inside so they are not recyclable.Some exceptions to the lined with plastic rule - like juice containers, milk containers, and aseptic containers. These materials are lined with plastic but they are bought back by their manufacturer to be recycled.If you have questions about recycling visit www.bouldercountyrecycles.org. And, remember Reduce, Reuse, Recycle and Compost.