i’m kinda new to the program, so I hope you can help a newbie 
I’m importing an obj file from maya into zbrush, and working on it, using 3dlayers and subtools. What if I want to save this? I know that to save a 3d model you have to save it as a tool instead of a projekt, but wont I lose all my layers and subtools? Thanks in advance
Tool>Save As saves all the current Tool’s SubTools and Layers. It also saves polypaint, and if you’re on the Mac it saves any textures that have been applied to SubTools.
(You do realize that you could have simply tested Tool>Save As and gotten the answer in moments rather than waiting for hours for someone to answer your post? ;))