Copy everything using CTRL-SHIFT-C (this a great trick I learned a while back, it copies everything on all your layers within the selection). Press CTRL-V to paste the new layer (Fig.44).
With the new layer selected, drag your line art layer over the mask icon. You should have something similar to the picture shown in Fig.45.
Unlink the layer and the mask by clicking on the chain and make sure you have the layer selected and not the mask (Fig.46).
In the top menu, go to Filter > Blur > Gaussian Blur and change the setting to the same as Fig.47 and click OK.
In the top menu, go to Edit > Fill and change the setting to the same as Fig.48 and click OK. In this case, I went and filled it with the same setting again, just give the line some more weight.
Now, throw away your mask and in the pop window, choose "Apply". Then turn on your effects layer and change your image to CMYK Mode, by going to Image > Mode > CMYK.
There you're done and you should have something along the lines of what can be seen in Fig.49.
I hope you enjoyed this tutorial, and I hope that it helped some of you out!