A common question I keep hearing people ask focuses on cheap and easy methods for achieving a ScreenToned look with a digital image. Screentone, in-case you have never heard of it, is a clear acetate-like material that has adhesive on one side and a field of dots on the other. It is used to create texture, value, and atmospheric effects in manga and some American comics. Each tone has a different density of dots used to achieve a certain value of Gray while keeping the whole image b/w. This method is used in newspaper printing all the time, so chances are you'll have seen an example or can find one quickly. in any newspaper you have handy.
As for technique, there are two ways of creating digital tones that I generally use. (I am describing this technique using Photoshop 7, but this might work for any program with similar filters and bitmap options.) In both Methods, Start by importing your line art and converting it into grayscale. ( Image > Mode > Grayscale ) Next, Create a new layer and set it to multiply (layers panel - click the box with "Normal" in it). Finally, IN THE NEWLY CREATED LAYER apply the appropriate grey tones (20%, 50%, etc.) until your artwork is essentially a finished image. Then ...
Method A.) Select the layer with the grey patterns that you've been working in all along by clicking on it in the Layers Palette. Find the filter
by looking here: Filter > Pixelate > Color Halftone. Run the filter. It will ask you for dot size in pixels ... The higher the resolution (in dpi) that your image has the smaller the dots will appear. Basically, Z , or UNDO, is your friend as you experiment through trial and error to find the right dot size. Another, problem I've read about, but have yet to encounter is that the dots will CHANGE whenever you resize your image, creating unwanted Moire effects. (Those funky optical patterns made by overlapping tones incorrectly.) The last stickler on this method is that you can't use it in RGB mode. If you do you'll get a multicolored dot pattern, even on greys ... sorta like what newspaper pictures look like up close.
Method B.)This is kinda tricky. Select all the lineart on the orginal layer and or it. Next delete the whole original layer leaving only the grey patterns on the new layer. Now go to Image > Mode > Bitmap. Select round dots in the first window and hit ok. Tweak the dot density on the second window to change the overall dot size for the end tone effect and then hit OK. Now that your greys are all Tone-ified, go Image > Mode > Grayscale in order to return you're image to a grayscale image. Don't forget this step, since you CANNOT paste in Bitmap mode. Now change the tone layer from Normal to Multiply. Add a new layer, and move it UNDER the tone layer by dragging it down on the Layer palette. Now select the new layer, and hit Edit > Paste. Your ink lines will be added and VOILA instant Toned Inks. I think this method looks the best IMHO. Checkout AP's How To Draw Manga #3 (the big collected one) as David Hutchinson has a REALLY good demo that uses a similar method. If you mess up the cut/paste stuff just use the History Panel to back up to before you deleted your precious inks. You can skip that cut/paste part, BUT you'll risk losing any delicate pencil or pen lines, since the Bitmap conversion is ROUGH (More like a sledgehammer than a scalpel.) I recommend removing your inks with the cut/paste method so that your inks turn out PERFECT and that sets the Tones off better than anything.
It's confusing to read, but just try following along, one step at a time, and it shouldn't be too bad.
I hope you find this useful!!
