Why don't you tell me? You FLAC dudes are the ones who can't read threat titles or initial posts.
Thread title: posits audio degradation via zip compression.
First post: explains that file size shrinks when compressing wavs via zip, guy wonders if it degrades audio quality.
The answer is that zipping has zero effect on the quality of an audio file, but that it doesn't compress the size by that much. This is known as DATA COMPRESSION.
Someone suggested FLAC, which is not data compression. Yes, it is lossless, but it performs an entirely different function to zipping.
Most DAWs don't support FLAC, and most people don't use Reaper. Sorry if that hurts to hear, but it's true. The fact that Reaper supports it does not in any way, shape, or form qualify it as an alternative to WAV files. Not in this case or in any other case.
The statement "zip is not good for compressing wav" is patently false. It's great for compressing wav files. It's great for compressing files in general. It's not great at compressing audio, but that's not the point of zipping in the first place.