A couple of years ago I looked into the behaviour of the Compress Options, I've recently revisited the topic in response to some recent Service Requests. My list of Communities content on the Compress feature has got a little longer, some updates have been added to the earlier pieces: What does 'Compress File on Exit' do? I was surprised to find out how little the User Preference 'Compress on Exit' actually does. ...

Younger readers can Google Letratone, the rest of you may remember fiddly scalpel work and just how hard it was to pattern a drawing! Here is a link to a cell library containing percentage dot screens that could be useful for giving a different 'old school' character to shaded areas. They will be quite efficient in 2D DGN vector graphics but will probably create massive numbers of elements if exported to other formats...