How to control the thickness and darkness of lines when exporting UV Layout I exported an UV Layout from Blender 2.8 and imported in Photoshop in order to build a simple displacement map.
All the UV lines are not black but a kind of black to grey graduation.
The lines are not 1 pixel wide but 2 or three.
I have tried every setting I can do in the Export UV panel, but I got always the same.
Here you find the original UV layout in Blender 2.8:

And here you will find the snapshot out of Photoshop with the strange grayish lines:

BTW, I have the same issue editing the same file in GIMP or other graphic programs. So it seems that the Blender 2.8 exporter is creating this behavior.
I had a similar issue with the edge being 4px. There are a couple of options but none I can see to fix this. Preferences > theme > UV Image editor. You can change the vertex size but not the edge. Also on the overlays there are no specific size options in the Display As



Instead I exported the UV Map as .svg or .eps from here you can open in Adobe Illustrator which gives a sharp vector path. I would set the fill opacity to 0 to make sure there is no bleed from the black edge. You could open either of these formats in Ps but the same issue persists.



In Illustrator you can then adjust the stroke width from 1pt to 0.1pt and copy into Photoshop to give a single pixel width. Not perfect but the best I can see unless there is another option I am missing in Blender