Zproject files getting to large, is there a smart way to keep the size down.
I don’t want to use HDsculpt becasue you cant’t export the HD information with obj files.
The project I’m working on right now is a character with lots of armor peices and ornaments, I’ve only sclupted the body so far and the tiles is over 400 mg large.’
Please Help 
yeah i’d like to know that aswell. I know that every tool you generate or open gets remembered and saved into a project file, so it can happen that besides your actual model with subtools , loads of other tools you created on the side to append as subtools keep getting saved seperately aswell. I remember there being a possibility to clear the tool list, but i dont remember how.
You can select tools from the tool palate that you no longer want and hit tool > subtool > delete on every subtool. This will remove them from zbrush and reduce the size of your project file a lot.
I did remove some other tools but it only reduced the size with 10 mg. need a better sulution for this.
Do you need to save the project itself (document settings, timeline, etc), or is it just a sculpt? If the latter, you could try saving just the ztl. Also go through the subtools and make sure they don’t have unnecessary polypaint/uv information.