I was experimenting with converting my 507 Mechanical Movements Posters, which are black and white line drawings, to a blueprint sort of look in PhotoShop. The obvious way would be to select all the white by color range and delete it, but I didn’t want to deal with messy pixels and jagged lines, plus that sounded kind of tedious.There weren’t any good resources online for doing it. Here’s what I came up with, which seems to work pretty well:
1) Select Image -> Mode -> Grayscale to convert your image to grayscale
2) Select Image -> Mode -> Duotone to open up the duotone dialogue.
3) Within the Duotone dialogue, select Monotone, and choose the blue color you want. I used #134c93 for my blue.
4) Select Image -> Adjustments -> Invert
5) Done! Enjoy your blueprint!