What you do is make a 1x2 document and zoom in 1600%. Then make half the canvas grey and go to Edit-> Define Pattern, and save it. Then open the image you want the lines on. Then Duplicate the background and put it adove the image. On the duplicated background go Right Click and go to Blending Options -> Pattern Overlay, then choose the pattern you saved. Then sent the Optacity to what ever you want.
Hope this helps. BTW this should go in mixed Art
*Moves*