Scanning Tips

Many type designers design their fonts directly on screen, without paper drawings as a source. This is fine, but even the best have been known to turn to the pencil and hand to get a curve just right. Then they need to somehow transfer that drawing to the computer and use it as a guide for drawing Bézier curves. Others of us, especially when working on non-roman scripts, rely heavily on drawings or other samples as the basis for new fonts. So, most type designers eventually need to get design info into the computer via the scanning process.

The nicest way to do this is to scan the drawing/sample and then bring it into Freehand or Illustrator (which allows drawing over a grayscale image). These programs, however, are not ideal for designing fonts. You will still need to get the outlines into Fontographer somehow. Note: FontLab’s ScanFont program may be the best scanning tool yet, but I haven’t tried it.

Here are some notes (compiled some time ago) that outline the process I’ve used with Fontographer and Photoshop on the Macintosh. All but the last section ought to be relevant whatever design program you use. These notes were compiled from a talk I gave to a few of my font design ‘apprentices’ in August 2001. Thanks to Steve Pillinger for his help in recording these notes.

Scan the image

Prepare the image for scanning.
1. If at all possible, do not use originals less than 0.25" high.
2. When possible, use samples that include the letters on either side of the target letter as a guide to spacing.
3. Especially for letters from rough-and-ready sources (e.g. printed books), choose several different instances of each letter. Scan each of them, and then assemble a consistent alphabet using the best. The smaller the original letters, the more scans are needed.
4. If the source image is your own drawing or calligraphy, add at least two horizontal lines (typically baseline and x-height). This will make it easier to align the image after scanning, and keep scaling consistent.
Put the original drawing as straight as possible on the scanner platen. You will later check to be sure the scan is aligned, but getting this at least close can help.
For ease, scan using a Photoshop plug-in, not the standalone scanner software. You'll be adjusting the image in Photoshop later, anyway.
Set plug-in settings.
1. Scan in grayscale. This preserves the edges of the letters better. You will be adjusting levels later to define the edges more strongly, so it’s OK if everything ends up mostly gray.
2. Set the scanning resolution according to the height of your originals. Each letter should end up around 300-400 pixels high (that seems to work best with Fontographer). For example, if your letters are around 0.5" high, then use a resolution of 600-800 DPI. If they are an inch high, use 300-400 DPI. There’s little reason to scan any finer than that if you're using Fontographer—it won't be reflected in the Fontographer background image and may even result in a worse background!
3. Be sure to use a resolution that is a whole-number factor or multiple of your scanner’s optical resolution. On a 300 DPI scanner, use either 150 or 300 DPI, not 200. On a 1200 DPI one, choose 300/400/600/1200, not 800 DPI.
Scan the image, whole page(s) at a time. Then you can adjust levels, etc. on all the letters consistently. If you need the letters to be in separate files, scan one big image, adjust, then copy portions into new, smaller files.

Adjust the image in Photoshop

Check each image for horizontal alignment. The easiest way to do this is to set a horizontal guide by dragging one out of the top ruler. Place the guide right at one of the baselines shown in the image. If the baseline is not absolutely aligned with the guide, use the rotate image command to fix it. I prefer to use numerical rotations (e.g., 0.7° counter-clockwise) with a lot of trial and error, because my hand and eye are not that steady!
Adjust the levels of the black channel. What you do in this step is critical to the weight of your resulting font! The end goal is to get an image that has a completely white background, and very black letters. Consult your documentation on details of how to adjust levels for your version of Photoshop.
1. Try automatic adjustment of levels first. This will, frankly, rarely suffice.
2. Adjust the left and right sliders to get a nice, clean background (without a lot of gray noise) and strong, clear letters.
3. Adjust the middle slider (the mid-range) to set how heavy the letters appear. Be sure that the result looks like what you want from your typeface. The adjustment of this slider (in combination with the left and right ones) can affect whether the font ends up having a light, regular, or semi-bold weight. It can also affect how sharp corners become—heavy, black scans tend to have more rounded edges.
4. If you have more than one image to process, write down the numeric description of the adjustment so that you can do an identical adjustment to other images.
5. Apply the adjustment and save your work!
Select the part of the image, and copy it to the clipboard.
1. Use the appropriate tool to select not only the target letter, but the letters on either side (if the original had letters spaced together). This will be a useful guide to spacing later in the design process.
2. Contrary to what others recommend, it is not necessary to draw any boxes on your original, or be careful that your selection is always the same height. The import process described below eliminates this need.
3. In some cases it may be useful to use Photoshop to convert the image to a bitmap image from the grayscale before this step—experiment to see what works best for you!

Import into Fontographer

Start Fontographer and open your font file (or create a new one).
Set font-wide font metrics. Before you paste anything, set some basic font parameters in the Edit/Font Info... dialog box (ascent/descent). This is to establish the position of your baseline.
Paste in the copied image. Open the character window for your target letter and option-paste the image (ALT-CTRL-V on Windows). This will place the image into the template layer. Be sure to use option-paste, not just paste. This will override Fontographer’s automatic scaling, which normally will resize the image to the em-square, with the result that letters end up scaled differently. Note: if you already have an outline or template image in that character location, and want to replace it, option-paste the image onto the character slot in the font window instead.
Rescale and align the pasted image. The previous step will usually result in a letter that is much too large, and misaligned with the baseline.
1. Go to the template layer, select the bitmap image by clicking on it, then shift-drag on one of the corners to scale it uniformly down (or up, if necessary) to the approximate size you want.
2. Then drag the image so that the image baseline is aligned with Fontographer’s baseline. Zoom in if you need to.
3. Continue to scale and align until you get it just right.
4. Alternatively, select the image and do all your scaling via the Element/Transform... dialog (using trial and error to determine the final correct scale factor). Then use the same scaling factor for other letters. You will still need to align each letter separately. If you plan to do this, you could skip the next two steps.
Set a second guideline. Go the the guides layer, click on the baseline and drag up to create a new horizontal guideline at the same place as your second drawn guideline (typically at the x-height).
Repeat the steps for all other letters. This time, use the baseline and new guideline as guides for alignment and scaling.

Draw the letter(s)

Do not auto-trace. It takes far longer to clean up an auto-traced image than to manually trace it. If you’re not feeling comfortable with drawing Bézier curves, then you’ll find cleaning up bad ones even more frustrating. I know it’s tempting, though. The one exception to this is if you are intentionally wanting a rough-looking font, such as one from typewriter with a bad ribbon.
Don’t follow the scan slavishly. Remember that, for the most part, you are wanting to design a font that is based on, not an micron-by-micron copy of, your original (if you wanted that you ought to be using a drum scanner and high-end tracing software). Feel free to depart from the scans when necessary.
Consistency may be more important than fidelity. The usefulness of most digital typefaces is dependent heavily on the consistency of strokes, so you will probably want to keep them the same width, even if that means ignoring inconsistencies in the scanned letters. Again, there are situations (such as with some typeface revivals) when you will want to retain inconsistencies.
On the other hand, shape is more important than consistency. Some amount of regularization is normal, but it’s easy to overdo it and lose some of the font’s character. Don't sacrifice key aspects of the letter’s shape for the sake of consistency, or to get a ‘perfect curve’.
Draw one letter, then use that outline as the basis for the next. For example, if you draw the n first, and get the stroke weights just right, then use that as the basis for h. Copy the outline from n to h, then extend the ascender up to the height as specified in the scan. Then go and change the serif shape if you want to. Use the scan as a guide to help you draw a good letter, not as a prescriptive source as to exactly how that letter should look. This is especially true if you are preparing a font from your own scanned drawings.

A note on ethics

Just because you can scan letters and turn them into a digital typeface doesn’t mean that you ought to. If they are your own drawings, or scans of pre-1900 books that you own, then you’re fine. But if, for example, you want to replicate a typeface that was produced by Monotype in the 1960's, then you need Monotype’s permission. If you are wanting to do a revival of a face from 1750, and you have photographs you’ve taken of a book in a library, then you ought to get permission from that library to use the images for a commercial purpose (assuming you wish to sell the font).

I’m not trying to be dogmatic here. I’m just trying to encourage you to support the companies that invested in the original typefaces and those institutions that preserve rare books (at sometimes great expense to them).