"Mastering" is a term that different people probably use slightly differently, but in my view it involves everything that means turning a typeface design into a shipping font.

Checking of the quality of outlines and their compatibility with requirements of font format specification can be seen as "mastering" though most people consider it a part of the design process.

Depending on one's perspective, writing code for OpenType Layout features can be seen as "design" or "mastering", since some people consider OpenType Layout as much as essential part of the design decision-making process as spacing and kerning, while others consider it more akin to hinting.

In some cases, hinting can be seen as making design decisions, but is more likely to fall into the "mastering" category.

Other typical elements of "mastering" include checking and fixing of: Unicode encoding, glyph naming, glyph ordering, family naming, linespacing consistency, as well as lots of other technical parameters such as embedding settings, version records, Panose information, and it some cases some additional technical parts.

Mastering is often tied directly to quality assurance (testing and proofing).

Currently, one universal checklist for all these aspects does not exist. But tools such as FontLab Studio along with the FontQA plugin, Adobe FDK (especially compareFamily but also other tools of the package), Microsoft FontValidator, Area51, FeatureProof, Microsoft VOLT & VTT, and DTL OTMaster can all be useful in the process of mastering.

Best,
Adam

In short, it's analogous to 'mastering' a vinyl record -- creating the master cut then used to create the stamps from which the final product appears.

This is my font mastering checklist.

Dunwich, thanks! This is a great list.

I have some questions for you. Sorry there are so many.

1. What do you mean by "final production directories"?
2. What is an "interpolated instance"? ( I keep trying to find out what exactly interpolation means in font design, and I still have no idea.)
3. "Generate kern files for instances"?
4. "Dekink interpolated instances with RMX harmonizer"? What does this mean, and what if I can't afford that app? Is there another way to do it?
5. What's an "interpolated font"?
6. What do you mean by "flat font"? I know what decompose is, though.
7. What are "glyph indices"?
8. What do you mean by "test final proof"?

Thanks again for all your help.

Oh, and thanks to twardoch too! Now I understand what mastering is. I just need to make sure that I do all of the right things, and do them correctly.

1. What do you mean by "final production directories"?

My font outlines make extensive use of overlaps and composite characters. Before I can use them to produce final fonts I have to break down many composite characters and remove the overlaps. To keep these “flat” files from getting mixed up with my original files I put them into their own directories.

2. What is an "interpolated instance"? ( I keep trying to find out what exactly interpolation means in font design, and I still have no idea.)

An interpolated instance is a font that was interpolated from two or more master fonts. Watch Erik's video for an explanation.

3. "Generate kern files for instances"?

I do my kerning in Metrics Machine and interpolate in Superpolator. I use Metrics Machine to export the interpolated kerning from my Superpolator UFO files to an AFDKO-compatible feature file that can be compiled into final fonts.

4. "Dekink interpolated instances with RMX harmonizer"? What does this mean, and what if I can't afford that app? Is there another way to do it?

Remix Harmonizer is part of Tim Ahrens Font Remix suite of tools. It's sort of like 1000-grit wet sandpaper for bezier curves. It can automatically fix “kinks“, which are funky math problems that occur in bezier curves as a result of batch processes, including interpolation. Basically, it fixes a lot of wonky little details that would take me hours to find and correct manually.

5. What's an "interpolated font"?

That's the same thing as the interpolated instance described above.

6. What do you mean by "flat font"? I know what decompose is, though.

A flat font is a flat with no overlaps.

7. What are "glyph indices"?

Each glyph has a index number that orders it within the font. For some reason this is the default order for the glyph palette in Adobe apps. Because I do not add glyphs to fonts in a logical order I sort them to match my logically-sorted encoding files.

8. What do you mean by "test final proof"?

I have a final test proof file that I use to make sure everything prints correctly in Indesign.

I'd love to see James's list but my computer can't read Numbers files. Any chance you or another typophile with access to it can export to Excel or some other more common format?

*double post*

@eliason a simple export to Excel http://cl.ly/2Q011g2m232E2f3S0f2O

Sorry for taking so long to thank you again Dunwich! I got super busy with some projects.

Thank you so much for all your guidance.

Okay that video you posted really helped me understand what that Superpolator is used for. It must be great to have when you want to generate different weights of your font. Unfortunately I can't afford it right now, so I'll have to rely on FontLab to help me with that for now. Same with RMX Harmonizer. That sounds great too. So does Metrics Machine. I wish I had all three.

Oh yeah the glyph panel in Illustrator, InDesign, etc. I'll take a look at how my glyphs are laying out in it and rearrange their order. If I can figure out exactly how, that is.

Okay I understand everything you mean now.

Thanks a million! You're the best Dunwich.