Sunday Mailbag

April 8th, 2007 | Posted in Mailbag

Q: I have some larger size artwork (like 18″x24″) to scan and I have not been able to find a home scanner that can scan this size. I have taken some stuff to Staples to scan on their large machine but it gets kind of expensive. Can you tell me if you have an easy way to scan large artwork? (I assume you scan your large pages for MAD??)

A: A full MAD spread is 21″ x 32.25″ at 200% print size, so I have this problem a lot.

I have a Microtek 9600XL 12 x 17 scanner, which is as big as they get for home use. I scan in sections and then overlap the scans in Photoshop, adjust the rotation/position until they match, and then flatten to one layer. There is no easy way to do this, but here is my process:

  • Scan each section, allowing as much overlap as I can (the more the better). It’s also important to realize that when scanning artwork that does not fit on the scanning bed, the edges of the scan that correspond to the areas where your art is extending past the scan bed will be distorted because of the slight ridge on most scanners. Therefore I either stop the scanning area an inch short of these edges, or I cut those edges off from the finished scan in photoshop. I try and establish one edge of the art as the “true edge” and keep that edge as the one I place against the scanners edges if possible.
  • Create a new blank file in Photoshop that is a little bigger than your actual art is. Make it match your scans in terms of mode (grayscale, RGB, CMYK, etc) and DPI.
  • Drag each scan to the new file, where they will be on their own layer automatically.
  • Use some frame of reference to adjust one of these layers so it is square with the edges of the new file. If you have any straight horizontal or perpendicular lines in your original image, this is a good thing to use… or you can use one of the edges of the image if you had hard edges. Get that file layer straight and in place.
  • Switch to the other layer, making sure it is above the one you just positioned. Change the opacity to 50%. Then move it so the overlapping areas match up. It will be easy to see if they do not thanks to the transparency. They usually don’t. Position the layer so one area does match perfectly… I usually pick an area on one side of the image rather than the center.
  • You may have to zoom out to do this part. Go to edit>image>transform>rotate. Now look for the little target symbol that will appear in the exact center of your layer. Drag it to the place where you exactly match up the overlapping images. This is your anchor point. Now rotate the layer until the other areas match up by going over to the other side of the image and moving the cursor to make the rotation.
  • I will erase some of the hard edge of the upper layer where it overlaps just to soften the transition.
  • Restore the opacity of the second layer, then flatten the image.

If you need more than two scans it becomes a lot harder, as doing multiple rotations will result in each being ‘a little off’ and nothing will exactly match up in the end. These consumer scanners are not perfect, and there will almost always be a little difference anyway, so no matter what some touch ups will probably be needed to fix these problems.

Thanks to Nick 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. totopo says:

    If your scan has a straight line, you can take the ruler tool in Photoshop and click on two points of that line, then go to Rotate Canvas and select Arbitrary and that angle will automatically be in the field. Click OK and you image is straight. My work generally has a straight line in each scanned section, so if I do this with each file the scanner creates, when I combine them in one document they are usually right on. Not sure if this will help everyone in this situation, but it’s good to know.

  2. grthomas says:

    I’m hoping that the photo merge in CS3 works as well for scans as it does for panorama photography. This will save tons of time.

    Just one of many places I’ve seen it on the web:


New profile pic courtesy of my self-caricature for the Scott Maiko penned article “Gotcha! Mug Shots of Common (but Despicable) Criminals” from MAD 550

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