Sunday Mailbag

November 25th, 2012 | Posted in Mailbag

Q: When you go from the “final pencilling” to “the inking,” what is your process of getting rid of the pencil lines? Do you simply erase them? Or are they not a problem once the pictures are scanned into your computer? Just wondering, because I want to get the cleanest final drawing as possible.

A: Erasing underling pencils from inked pieces is every cartoonists bane. There are a number of ways to help make it less painful. Which one would work the best for you depends on your drawing technique, the final effect you want to achieve with your cartoons, and the way you prefer to work.

One method is to draw in a non- repro blue or red pencil, and ink over that. This method was a lot more popular in the days of stat cameras, as they would not “see” the non-repro color when shooting line art, and so no erasing or further messing about was necessary. Today’s desktop scanners are much too sensitive to completely ignore non-repro colors like that, so you need to do some magic in PhotoShop in order for the lines to go away in the scan. I don’t do that technique, so I have no suggestions as how best to do it, but a simple Internet search for “remove blue sketch from scan” will yield dozens of different methods, most involving the cyan channel.

Another method that involves no erasing is to never do a pencil sketch, at least not on the final board. This involves the use of a light table to ink right on a blank board overlaying your original pencil sketch or a copy of it. I sometimes use this method when I am in a rush, and when the piece I am working on is a little less involved than, say, a MAD parody page. I’m not a huge fan of this technique because I find it hard to stare into a light table for a long time, and find it messes with my ability to see the detail I am working on. I will say that since I got one of those awesome Artograph LED light tablets it’s much easier on the eyes to use a light table for long periods. One trick that makes this work better for me is to not work in a dark room with the light table. Some ambient light, even using my table lamp indirectly, will both give my eyes some reflective light to see and a better feel for the board surface, and will “lighten” the pencil sketch image so I draw more and trace less with the inks. I’d use this method if I did a comic strip or some smaller format illustrations, as it would be easier to do working with a smaller piece.

Finally, there is always the old fashioned method of actually using an eraser to erase the sketch lines after inking. You will probably stilly end up with ghost lines no matter how hard you try and erase everything, and there are other problems that crop up. Some depend on how you scan the work after erasing.

First, the way you draw matters in ,how easy it is to erase. I’m a heavy-handed penciller, so that’s a problem for me. I use a harder pencil like an HB, F, or 2H, rather than a 2B. This forces me to be lighter with the lines as the harder leads will score the board if I press too hard. Harder leads erase more fully as well.

Another thing I will do is “knock down” the pencil lines a bit before inking. I find the ink will sometimes not adhere to the boards as well if there is a lot of graphite under it, so knocking down the pencils will make the inks less susceptible to lightening when erasing later. All I do to knock down the pencils is take a kneadable eraser, roll it into a longer tube shape, and roll it over the drawing like a rolling pin flattening pizza dough. This removes excess graphite and lightens the drawing a bit, making inking easier.

Second, the physical act of erasing. I erase my lines using a combo of kneadable and plastic erasers. That takes elbow grease and some time. I start out with the kneadable eraser, since that leaves no crumbs and is less hard on the board. That will not get everything, as you can’t apply much pressure with the kneadable. Then I switch to a plastic eraser, and really bear down. I hate pink erasers, as they will literally stain your board at times. Gum erasers crumble away too easily. Plastic ones don’t mark up the board, last longer and seem to be the least hard on the surface. When erasing, you have to get your nose in close and look for the areas you missed with the kneadable. The inevitable crumbs will get in your way, but if you have one of those board brushes to sweep them off keep it handy and do it many times while you are working on the board, not just at the end.

How you ink makes a difference as well. Erasing can beat up the board surface, and your inks can get compromised as a result. This is especially true if you use a brush or a combination of pen and brush. Brush inks use less ink and don’t soak into the board fibers as deeply, so they may lighten up when you erase them over. To compensate for this, I use a different ink when I do brushwork . . . something really dense like Dr. Martin’s Black Star will stay nice and black even if you erase hard over it.

Finally, how you scan and prep your line work will help clean up the drawing. If you scan your inks in as line (i.e. bitmap), whatever extraneous pencil lines are left will probably be eliminated. I usually scan my inks as grayscale images because I use some value-dependent effects like washes and lesser marker lines that need grayscale to be picked up. Unfortunately that also means ghost or missed pencil lines will still get picked up. There are a few ways to eliminate these strays.

If your final art needs very stark, clean inks like a comic book or comic strips (no washes or other values in the work), you can use a threshold adjustment in PhotoShop to clean up the scans. In your scan in PhotoShop, go to image > adjustments > threshold and set at 118. This really drops out the grays and sharpens the line work. Just make sure your scan is at a high resolution when you to this. I’d recommend scanning at 600 dpi, doing the cleanup and then reducing to whatever dpi your final needs to be at.

I need to keep the integrity of some lighter values in my inks, so I use the levels adjustments to do the clean up in grayscale mode. Usually changing the lower end to 20 and the high end to 230 will do the trick.

Whew, and you thought that would be a short answer!

Thanks to Michael X. Martin for the question. If you have a question you want answered for the mailbag about cartooning, illustration, MAD Magazine, caricature or similar, e-mail me and I’ll try and answer it here!


  1. Mike says:

    I’ve never expected a short answer from you, Tom, which is one reason I enjoy reading your blog. It is very informative. You are a great teacher!
    Thank you!

  2. Lee Fortuna says:

    Tom, I’m about to go to a light box to transfer my final pencil to Strathmore 4ply Bristol board but my light box has only one 15 watt bulb, in your opinion will I have trouble seeing the final pencil? This will be my first time using this light box, I’ve always used an overhead projector & traced the projected image on my final paper.

    • Tom says:

      Lee- That would depend on how thick your sketch paper and final board are. 15 watts isn’t very bright, but it could be plenty if both are reasonably thin. A 2ply or 3 ply bristol board for the inks would be as thick as you could probably use. If you did the sketch on a thicker piece of paper, you could scan it and print it out on a piece of regular copy paper, or go to a copy place and get a regular copy of it. Copy paper is pretty thin and allows more light through. Otherwise eliminate as much ambient light as you can to get maximum lightbox effect.

      • Lee Fortuna says:

        The original pencil sketch Tom is on a sheet from one of those Canson 8.5 x 11 hardcover black sketch books and does not say the “grade paper” it is, but it isn’t very thick at all. In fact after comparing it to copy paper, it seems very close in thickness that after holding against a glass door, i can see through it just about the same as copy paper. Well thanks for the scan tip Tom and I think this should go well! And if not, I’ll breakout the ole projector,lol!


Atlanta Caricature workshop wraps up today! Check my other 2018 workshop locations:

Workshops Ad

Dracula ad

Doctor Who Ad

Superman Ad

%d bloggers like this: