Textures - vanilla-like texture creating method - black outlines?

[TrueDestroyer]

How are the black outlines on all objects and all in game art created? Which program is preferred to work on the textures, that gives option to do this automatically? What is the recomended width for this outline? All these textures seem to have it the same, also some modders managed to create their own textures with this vanilla black, partially transparent outline. I managed to get it by copying existing parts of art only... What's more it's not only an outline, it's something like a black brush with certain set up, pressure, and width. What tools should I use to make it look like the textures are vanilla?

[kaptain_kavern]

* kaptain_kavern is summoning Shinzy, mrofa, rooki and all the others awesome graphists we have in there 

I'm really useless for all graphic related matters but I'm pretty sure with Gimp and Photoshop there is an outline option. As simple as that. I'm not talented enough to tell you how to set shader and/or alphas setting to managed the transparence though

[TrueDestroyer]

Ohhh so there is an automatic outline option:) I used some Photo Filtre (20% functional photoshop knockoff) program, but I'll turn to gimp I guess. I don't have any problems with transparency though:D

[kaptain_kavern]

I really hope someone better suited than me came to precise things more, but yes I'm sure about gimp because I do it often : there is an option to outline selection or object/layer

[theubie]

The option under photoshop is called stroke.