I have had best success going via (vector) PDF. The PDF is made using a print driver, from the normal printing dialog, giving you control over line weights and screening, merge/overwrite etc. The PDF gets imported into PS as transparent except for the (usually black) lines, with an assigned ppi resolution to deliver the desired output pixel dimensions out of the PDF's page size. I have a PS Action that takes this layer, flattens it for visibility in future editing, changes its blend mode to Multiply, and moves it to the top of the layer stack with a blank layer underneath. The colour goes onto this lower layer, or further layers as needed, with the lines overlaying all that. The lines layer can be edited to suit, adjusted with levels or curves, and its opacity changed or blend mode changed, to get an effect that is suitably crisp or soft.