Thank God for ZappLink 3! It allows you to use Photoshop (or other image editing programs) with Z-brush 3.1. This allows you to better manipulate texture files onto your model and allows for hard core masking (If you use Tool -> Masking -> Texture to INT). The only good option up to this point was to use the projection brush. Hopefully this will give you some usefull tips for working wih ZAppLink with Photoshop.
Here is my workflow to overcome streching and other tips
- I save files out seprartely to comp in photoshop to overcome the dreaded streaching. It seems as though zAppLink 3 doesn’t honor layer mask from my pliminary test but this is no big deal if you save your files as you do each projection and then mask out problem areas later in Photoshop(or delete out sections that will project arcross sections close to perpendicular to the view on each projection). For maximum flexibility save individaul views and compilie them in photoshop useing layer mask after projecting every view.
Click on the Texture Button with texture selected and hit export to save the Texture after each projection.
Streching Example below.
GET THE BEST RESOLUTION TIP
ZAppLink Texture Resolution is based on your screen Resolution And SubDivision Level. Set both as high as possible for best results. Frame you subject to fill as much off the screen before sending to Photoshop.See Below for example how to change screen Resolution. TIP: Hitting Pro will alow you to stop constraining highth to width ratio.
You need to set your texture resolution before converting the PolyPaint into a Texture Map or else you get the default 1024X1024 map which is pretty good but I recommend going up to 4096 if your machine can handle it. I beleive that 4096 is the highest that Maya can handle in Hardware Rendering. This will give you a better resolution and thus more detail in you Defuse maps. Type in 4096 for Height and width and hit new. Currently I am only able to handle the default 1024 Map. 
TIP 
ZApplink Shortcut CTRL+Shift+S
Converting from PolyPaint to a Texture File. (You need to set up UV’s before this. If you don’t have UV’s or arn’t sure I would go to TOOLS->TEXTURE-> GUV Tiling while in your lowes subdivision)
Here is some shortcut’s for working in Photoshop. In this example I set up multiple views for Z-appLink in the DOCUMENT-> prefreences. Note that if your adding a texture you need to merge it down to the default layer given when entering zApplink. Shortcut CTRL+E to merge an active layer down. The warp tool can come in really handy in photoshop for getting textures to line up. While in transform mode on a layer CTRL+T Right click to enter warp mode in Photoshop CS 2 or 3. Drag the points on the grid to get your textures to line up.
