Documents = 2.5d, and will export as photoshop document (.psd)
For 3d models, you'll want to save the tool (on the top right of your screenshot, you can see the 'save as' in the tool pallet). Tools can also be exported as .obj
There's no going back in this particular case.
Its a mistake a lot of people make when they first use zbrush, but the program itself usually tries to warn you. From Page 19 of the Getting Started Guide:
Document (ZBR file format): Saves pixols, only! This format is meant for creating
illustrations. Any 3D data (if your model is in edit mode) is converted to
2.5D data when saving as a document. (Document > Save or Document > Open)
Tool (ZTL file format): Saves polygons. Use this format to save a model as 3D data that you
can continue to work with in edit mode later. This format will also save any maps that are
applied to your SubTools via the Tool palette. (Tool > Save As or Tool > Load Tool)
ZBrush calls anything that can be used to add pixols to the canvas or modify
pixols already on the canvas a Tool. Since 3D models can serve this purpose,
they fall under this classification as well. Even though some tools are called
brushes, they serve a very different purpose from sculpting brushes (which are
found in the Brush palette). Click the link at the bottom of this page to find out
more about Tools in ZBrush.
ZProject (ZPR file format): New to ZBrush 4 is a format that saves considerably more data
than the ZTL format does. This format will save the document settings including size and
lighting, all materials that are used, the model itself and even the size/position/rotation of the
model on the canvas, render settings, Timeline and more. In short, using this format allows
you to return to ZBrush exactly where you left off. Keep in mind that this also results in a
much larger file size than the ZTL or ZBR formats.
(File > Save As or File > Open)
Replies
For 3d models, you'll want to save the tool (on the top right of your screenshot, you can see the 'save as' in the tool pallet). Tools can also be exported as .obj
There's no going back in this particular case.
Its a mistake a lot of people make when they first use zbrush, but the program itself usually tries to warn you. From Page 19 of the Getting Started Guide:
Document (ZBR file format): Saves pixols, only! This format is meant for creating
illustrations. Any 3D data (if your model is in edit mode) is converted to
2.5D data when saving as a document. (Document > Save or Document > Open)
Tool (ZTL file format): Saves polygons. Use this format to save a model as 3D data that you
can continue to work with in edit mode later. This format will also save any maps that are
applied to your SubTools via the Tool palette. (Tool > Save As or Tool > Load Tool)
ZBrush calls anything that can be used to add pixols to the canvas or modify
pixols already on the canvas a Tool. Since 3D models can serve this purpose,
they fall under this classification as well. Even though some tools are called
brushes, they serve a very different purpose from sculpting brushes (which are
found in the Brush palette). Click the link at the bottom of this page to find out
more about Tools in ZBrush.
ZProject (ZPR file format): New to ZBrush 4 is a format that saves considerably more data
than the ZTL format does. This format will save the document settings including size and
lighting, all materials that are used, the model itself and even the size/position/rotation of the
model on the canvas, render settings, Timeline and more. In short, using this format allows
you to return to ZBrush exactly where you left off. Keep in mind that this also results in a
much larger file size than the ZTL or ZBR formats.
(File > Save As or File > Open)