Hex2 painting is super great however sometimes I want a little more or to edit the paint file. Currently the painting tool in Hex2 doesnt support layers although you can blend by using the opacity. (I think they do more with layers and brush angles in a future update). Maybe someone else have better way but I find the following additionally usefull to paint/edit outside Hex in my graphic app. and then go and do more again inside Hex.
1 After the model has been UV mapped in Hex2 then you must apply a material to the model as a texture map before Hex2 will allow the model to be painted. A png file is generated automatically.(map1)
2 If the model is exported then as an Obj to Carrara, you can generate another UV map in the modeling room and export it (make it the same size eg 2048X2048, as the texture map in step 1.) This map has the wireframe showing
(map 2)
3. In my graphics app I open map 1, add map 2 as a semitransparent layer so I have a wireframe guide and then I can happily paint away in layers to my hearts content (NB I have to rotate map2 180 degrees to match map1 - is currently a small inconvenience in H2/carrara talking to each other)
4 I collapse the layers, and save as my original Hex2 texture png, reopen Hex 2 model and carry on painting as before.
cheers
Tony