So, now that I have a line I can be fairly settled with, its time to color. There are a lot of ways to approach this, but one of my favorites is to separate the ink layer and paint layer. This is my formula - it is for Apple computers, but I'm sure it works just as well for any Photoshop version. If you have better ways of doing this, by all means post a link to your particular formulas. I love learning different ways of doing these things.
These are the first steps. Next post will have the others.
CONVERTING IMAGES TO INK AND PAINT LEVELS
Scan image at 300 DPI or higher in GREYSCALE mode. If the image is in color, you should convert it to GREYSCALE before proceeding
Optional step. You need a clean line against a white background. Pull down from IMAGE (top menu) and select ADJUST, then click on BRIGHTNESS/CONTRAST. Use the sliders to sharpen and define the line without losing too much of the look if it is a pencil drawing. Click OK when you are happy with the line work.
This is your big chance to perfect your drawing before getting into a mess later. Using PAINTBRUSH or ERASER tool, erase anything that you dont want or add anything that is missing. Adjusting lines will not work well after this point.
Before proceeding, flatten your image. Label this single, remaining layer BACKGROUND.
Find the LAYERS box in the lower right of your screen. Click on the little black arrow in the upper right hand corner of the box, this will show a menu. Click on DUPLICATE LAYER
A box will appear and ask you what you want to name this layer, label it INK then click OK.
Be sure the INK layer is above the BACKGROUND layer.
Select the INK layer. Pull down from SELECT (top menu) and click on COLOR RANGE below it. The COLOR RANGE box will appear and a SAMPLED COLORS indicator will be apparent. Your cursor will now look like a eye dropper - use it to click once on any area that is clean white space: do not click on the line work. A little preview window will give you a rough idea which lines have been recognized. Now notice the FUZZINESS slider. Slide it back and forth till you are happy with the image in the preview window. (I usually slide it all the way to the right - Fuzziness 200) Click OK.
NOTE: After clicking OK in the last step, the lines on your drawing should now be stripey and moving - these will be the ink lines that float above the paint layer of your picture.
Go back to the LAYERS box and repeat the procedure in step 4. (The INK layer in the box should be highlighted before you click on DUPLICATE LAYER). When the box comes up and asks for a new name, label this one PAINT.
Now you have several different layers in the LAYERS box. You can click and drag them around to put different ones on top. It is necessary to keep the INK layer on top, then the PAINT layer under it, followed by the BACKGROUND layer that is left.
Highlight the INK layer in the LAYERS box and push the DELETE button on your keyboard. This deletes the white areas from the INK layer. I dont know why but it does.
Notice the little human eyes to the left of each of the layers in the layers box. Click on the ones next to BACKGROUND and PAINT to make them disappear, leaving the only remaining eye visible next to INK. This gives you a weird gray checkerboard pattern on your image, this is correct at this point, it also reveals how your final line is going to look.
Go back to the LAYERS box, and with the INK layer highlighted, repeat the procedure in step 4 yet again, this time labeling this one CONTROL. Remember to keep the layers arranged with INK on top followed by PAINT then CONTROL and finally BACKGROUND on the bottom.
Now, while the CONTROL layer is highlighted, set your color palette to PURE WHITE. Choose the PAINTBUCKET from the picture menu, position it over any blank white space on the drawing. Click the PAINTBUCKET into any blank, white spaces. This should eradicate the little checkerboard pattern. Inevitably, the paint won't flow into every nook and cranny on the drawing, so use a big brush to wipe the whole thing thoroughly. Be sure no gray checkerboard is left.