As you can see there is a fine line in this picture that is slightly darker than the rest (this will indicate the folding line in the end). I created it by making a rectangle with the
Marquee Tool, then I clicked on
Image > Adjustments > Exposure and then I set the
Gamma Correction to
I want exactly this line as a dotted line and at a very specific place (specific coordinates) and specific height.
I managed to get the height correctly by carefully drawing. I'm struggling with the specific coordinates, I tried changing the y coordinate in the Canvas property on the right, but that actually cut out the rectangle and pasted it at a different location, similar to the selection tool in paint.
Additionally, I don't know how to turn this rectangle into a dotted line.
How can I achieve this?
I also have Illustrator if that is easier.
Edit: What's important is that I can set the exposure of the line so that it "blends" in with the background