deskthority

These photo are focus on the quality difference about various buckling spring IBM keyboard.

Dye sublimation quality: Model F > IBM Model M(metal logo) > Lexmark Model M(Grey logo) > IBM Brother buckling spring keyboard
Model F having the perfect all black Dye sublimation but not double-cap. IBM Model M(Metal logo) is the best quality on double-cap.

PBT plastic quality: Model F = IBM Model M(metal logo) > Lexmark Model M(Grey logo) > IBM Brother buckling spring keyboard
The IBM Model M(metal logo) did the work to prevent the deformation on the keycap(pic5) but the Model F didn't.

01_Top of keycaps

02_Upperside keycaps

03_downside keycaps

04_left side keycaps

05_bottom of keycaps

Ooh, this is lovely; I was wondering for a while what the difference between the dye subs for metal label Ms and Fs was, since the former seemed so nice already!

I think you are missing the last generation of Model Ms sometime after the Lexmark takeover though; The dye sub quality for your "Lexmark" Model M could also be seen in late IBM Model Ms (I think starting sometime in 1989?) and I guess persisted in early Lexmark models (maybe up to 1992/1993 or so).

However, the late Lexmark Model Ms (definitely the ones with the crappy back label) had absolutely horrible legends, really blurry. They also stopped dye subbing the text on the number pad, as well as the Alt/SysRq, a different color. Not as bad as Unicomp's dye subs, so I guess that's something.

Very good info's terrycherry, thanks for the great work!

Brother buckling spring looks the worst IMO.

The model F and square label ones look fantastic as usual. I wonder how Unicomp dyesubs would fare in this comparison?

They're pretty blurry, and badly aligned, if my RGB mods are anything to go by.. They're at most as good as the late Lexmark dye subs. Fohat said they recently got a new dye sub machine, sure doesn't look like that's the case though.

Wow, excellent, what a nice comparison! Thanks for these pictures!

The Model F is an AT or F122, I'm assuming? Would be awesome to see the differences between F XT, AT and F122 in there as well .

Yeah, now that I think about it, I remember people saying that the XT had the best legends. I'd definitely like to see the differences between the various Model Fs as well.

emdude: I think the IBM made(grey logo) between Lexmark brand label keycap are nothing to compare with.
I think the IBM made(grey logo) keycaps should same as the metal logo.
The keycap quality got bad when the model M transferred to Lexmark so I think the blue logo would be same as the Lexmark(grey logo).
My Lexmark(grey logo)keyboard was made in 1994.
My mode F is 5150 keyboard from 1984.

I own an '87 (IBM) and '89 (IBM) Model M with legends that show a discernible difference that appears to go beyond production tolerances. I will try to take a photo later..

My metal logo was made in 1986.03.25
And the thing is the different logo and brand means the quality changed so I don't think the production year is the factor to determine the keycaps quality.

Sorry, I should have clarified that the '87 was a metal logo and the '89 was a gray logo. I also have other Model Ms, from '86 to '88, with the label superseding the barcode-style label with similar legend quality. I think quality standards may have changed in sometime in '89 to coincide with the new label style. I've noticed some differences with Model Ms made starting this year, like things like a thinner steel plate, less bold legends, etc.. I'm not sure about later years though.

For example, the label style that came after the barcode-style labels: And then subsequent revision, in 1989: Anyhow, my point is that IBM appeared to do cost-cutting even when they were still producing the Model M, before handing things off to Lexmark. The 1390120, the 1390131, and the earliest (pre-'89) 1391401 Model Ms seems to have key caps of consistent quality. I think in '89 quality declined, then when Lexmark took over IBM's keyboard division in '92(?), quality declined again. Sorry, I still need to get photos..

Okay, sorry for the potato pic, but hopefully this illustrates it a bit better:
From left to right: 1390131 (IBM, 1987), 1391401 (IBM, 1989), 82G2383 (Lexmark, 1994)

Noting even comes close to the model F keycaps and XT in particular. Good job with the photos.

Not the clearest pic, but just for fun


From left to right:
XT, F107, F122, Rubberdome M, Unicomp (2016)

Thought this might be of interest.

The XT caps are pretty much the pinnacle of IBM, imo. They seem to reach a level of saturation and tasteful thickness that other 'boards can't match.

I like them so much that my avatar is a macro shot of an XT A.