I don’t know about monospaced fraktur (maybe there’s a revival of some typewriter face out there, there are for Irish ones).
As for low contrast, just the first ones I came up with:
http://www.underware.nl/fonts/fakir/
http://www.type-together.com/index.php?action=portal/viewContent&cntId_c...
http://www.myfonts.com/fonts/thometz/hefeweizen/
http://www.myfonts.com/fonts/resistenza/afrobeat-gothic/
http://www.myfonts.com/fonts/doubletwo/xxii-blasphema/
http://www.myfonts.com/fonts/hubertjocham/keks/

Assuming you mean fraktur in the broader sense of blackletter,

There was a monospaced Old English for the IBM selectric typewriter

Almendra Display, a monoline blackletter.

Actually I'm looking for a fraktur specifically. I find blackletter strangely beautiful (I say "strangely" because typically I admire legibility, and blackletter tends away from that ideal) but I have real difficulty classifying them into one of the four major families. (And then there are modern blackletters, which sometimes don't fit into any of them!) Part of my hope is that by looking at designs with certain constraints (like the monowidth or monoline mentioned) then I would better be able to identify the elements that are essential to that style. I'm still trying to learn about their history, as the difference between historical and contemporary letter forms, for example, still throws me. It can be hard to compare apples to apples.

Furthermore, I like to include a healthy range of math symbols in my own designs, and I'm never able to make fitting ℭ/ℌ/ℑ/ℜ/ℨ because I don't understand them.

All that said, I'm looking for blackletter specimens to study, starting with fraktur. If someone has developed their own mnemonic system for quickly classifying blackletters, I'd be all ears.

Have you seen this?
https://en.wikipedia.org/wiki/Fraktur_%28script%29#mediaviewer/File:Gebr...

This could be interesting:
http://letterology.blogspot.it/2012/09/typewriter-blackletter.html

A monoline fraktur:
http://www.google.com/fonts/specimen/Astloch

As an exercise, I tried classifying all of Steffmann's blackletters that are listed on 1001fonts.

Don't want to rain on the parade but I have compared an assortment of Mr. Steffmann's fonts with digital fonts created earlier by others and found that -- after standardizing the glyph sizes -- the digital outlines were point for point identical. The only differences being that he had added some glyphs to make the fonts more complete. I didn't compile a comprehensive list, but some specific ones are in posts to the font ID forum -- which unfortunately is not indexed.
Don

Good book list! Also:
http://books.google.com/books/about/Mexican_Blackletter.html?id=lpkVAQAA...

hhp

For what is in effect a digital encyclopedia of Fraktur see the fonts digitized by Gerhard Helzel http://www.fraktur.biz/ For some comments on Mr. Helzel's project see the following web page by Luc Devroye http://luc.devroye.org/fonts-23582.html
Luc Devroye also has an extensive web page on Fraktur http://luc.devroye.org/fraktur.html Many hours of useful reading with links to samples and specific fonts.
Don

You mentioned Math Symbols. Karsten Luecke designed a legible regular and bold traditional Fraktur alphabet for this purpose

Herr Steffmann has made no secret that he often "merely" adds accented chars to PD fonts. I simply used that collection for this exercise because it was the first name to come to mind when I thought "blackletter collection".

And thank you for all the links to resources.

So could somebody edit his Wikipedia entry so it doesn't say "has created over 350 fonts"?

hhp

That document is in the "draft" space; it's not a real article. The "created" language is what is used by 1001fonts.

I have not checked all of the digital sources for Mr. Steffmann's "created" fonts, but I have found ones that IMO the fontmaker who made them from non digital sources did not intend that the fonts be considered public domain fonts that could be edited and redistributed by others without permission.
Don

If you want to discuss the legal status of Herr Steffmann's fonts, please start a different thread. This one is about learning about identifying, classifying, and designing fraktur.

No I don't want to start a discussion about Mr. Steffmann's fonts. It could be endless. I was merely responding to your post that
---start quote--
As an exercise, I tried classifying all of Steffmann's blackletters
---end quote---
and your link to a wiki webpage that claimed that he had "created" them.
I will say nothing more about the topic unless his fonts surface again.
Don

For a contemporary monolinear (but not monospaced) Fraktur, see Rostrot by Georg Seifert:

This modernized blackletter started out in 2006 as a graduation project at the Bauhaus-Universität Weimar. Georg Seifert tried to answer the question how Fraktur typefaces would have looked like today, if they hadn’t fallen out of fashion. In Georg’s hands, the old Teutonic letterforms had to undergo the same stylistic shifts and transformations as Roman typefaces did: less ornamentation, a simplified construction, and a drastically reduced contrast. The result is a “grotesque” monolinear blackletter, Rostrot, and its “seriffed” sister style with some contrast, RosenRot. The fonts were never officially published, but come bundled with Judith Schalansky’s book Fraktur Mon Amour. — Fonts In Use

Rostrot seems very nice! Wish there was a general-release version.

Florian, thanks for mentioning Rostrot. I had seen promos for Grimms Märchen ohne Worte by Frank Flöthmann before and wondered whether there was a full alphabet of the font used on the cover.
As far as I can determine Rostrot was not included in the CD of fonts bundled with Fraktur Mon Amour http://www.fontblog.de/picts/FrakturMonAmour.pdf
Unfortunately, I no longer have access to Fraktur Mon Amour. Was the full alphabet printed in the book? Is it possible to show a specimen here?
Don

O.K. with some digging I found this

I should have been more specific: Rostrot and RosenRot came bundled with the second edition of Fraktur Mon Amour.
At least Rostrot Statisch has alternates for k and y (not for w, though):

Thanks Florian. Alt _k_ looks good.
Don