Possibly helped by 72c3a5f0f32f553a1f8abee2494f31d29b976383. We need to clarify how the images above were obtained - it seems there might be differences between the subs' appearance in the preview and the output DCP.

Anything else known about circumstances?

I don't see that issue in 2.14.48 (Mac), subtitles are nice and smooth, both preview and burn-in.

I remember that at some point you disabled font smoothing because of color fringing introduced by some font smoothing schemes. The missing font smoothing may introduce some jaggieness.

I've sent a mail to the reporter to check; I'm pretty sure it was 2.15.x, and the fix mentioned above reverts some changes to text rendering to make it the same as 2.14.x again. So if you're seeing good results on 2.14.x hopefully that fix will be all that's needed...

I see some similar artefacts in the player at half or quarter decode resolution with burn-in subs - as one would expect.

Also don't see issues with 2.15.135

vlcsnap-2021-04-21-00h53m18s838.png (36,016 bytes)   

vlcsnap-2021-04-21-00h53m18s838.png (36,016 bytes)   

Yes the fix has been in for a fair while (since 2.15.104 I think).

Ah, okay, I thought it was a current issue. The only older version I have is 2.15.30, don't see it there either.

vlcsnap-2021-04-21-09h52m45s882.png (36,016 bytes)   

vlcsnap-2021-04-21-09h52m45s882.png (36,016 bytes)   

OP reports this is OK now.