Anti-aliasing aka font smoothing

[Quoth]

Originally Posted by Aleron Ives

You can disable ClearType in Windows, but be advised that most modern fonts are designed to be viewed with AA, and they look horrible without it. You will need to stick to old fonts like Arial, Tahoma, Times New Roman, and Georgia that were created before font AA if you want legible text without ClearType.

Clear type is sub-addressing the RGB by colouring the edge pixels. Regular anti-aliasing uses whole pixels and is separate from Cleartype. Also at sufficient resolution the screen doesn't need AA. There is ALSO font hinting, which on Linux can usually be off, medium or aggressive. These are three different things.

You will need to stick to old fonts like Arial, Tahoma, Times New Roman, and Georgia that were created before font AA if you want legible text without ClearType

Anti-aliasing and hinting existed before MS Cleartype. As did desktop publishing on Mac OS before Unix based OS X, Gem, Win 3.x, UNIX/Solaris systems and even CP/M.

Cleartype was introduced only in 2001 on XP and was off by default. A later powertoy let you tune it on XP. On by default on Vista.
It and similar systems must be "tuned" for the actual digitally connected panel in use and not all are suitable.
You can certainly have whole pixel anti-aliasing and it existed even before IBM PC was launched! C code was published for anti-aliasing (which apples to text and graphics) before Windows existed.

Font hinting is a separate thing. Not all fonts have it.

Look it up.

[JSWolf]

Kindles need font hinting. Look at what happened when Amazon removed hinting from Bookerly.

[LostHisMarbles]

Didn't equate them, i said that it's a noticeable/readily discernible difference, making sense given the multiple pixels involved for every single "logical" one.
You are by all means free to test this out yourself with a modern font, ie one designed to be antialiased from the getgo.

Not sure who told you it's a pseudo-increase, but we may agree to disagree
Likewise for its only ever been needed on lower res displays..? I'd say on the very contrary, you need some decently high res before you can be the judge; try the nano texture 7,5K apple monitor. With and without subpixel AA.

Then get back to me, shall you?

As to retina mode "always on", i assume it depends on one's personal experiences/devices used? If locked?
I've found a healthy number of readers and viewers where this is controlable, from free ones to highly expensive ones.

[Quoth]

You are confusing native pixel anti-aliasing in Apple Retina mode and subpixel anti-aliasing (such as Cleartype) which uses coloured edges on fonts to effectively "sub-pixel" address to increase apparent resolution in horizontal direction on compatible displays. That type of subpixel addressing only works if the RGB stripes (or similar layout) is vertical.

Using physical pixels on a retina display (Apple only term) is not subpixel addressing.

At all resolutions using hinting on small fonts is important.

[Quoth]

Because Win10 & Win11 are mess on the GUI, the Cleartype may be only in particular programs. Some can use it even if off at system level. MS kept adding new incompatible APIs for the GUI after Server 2003, hence the mess.
Win8 worked differently for Desktops and Tablets (no Cleartype). In Win10 & Win11 the Cleartype can be forced on at the GDI level and then programs that otherwise never use Cleartype (due to API used) will be rendered with Cleartype (Which is for lower resolution compatible screens only).

Anti-aliasing (AA) being used is separate from Cleartype AA (text only) or any similar RGB subpixel scheme on Apple or Linux. Anti-aliasing works without sub-pixel (RGB) addressing and also for graphics.

Using native pixels on 2 x 2 Retina mode (HiDPI mode if not Apple) for anti-aliasing isn't sub-pixel addressing.

[olivila]

Interesting discussion — especially the part about handling formats and device performance. I’ve seen similar behavior when managing larger digital libraries where file optimization and proper metadata structuring really improve loading speed and navigation.

Even outside ebooks, the same principle applies when dealing with resource-heavy files or interactive content — clean structuring always enhances usability across devices.

Appreciate everyone sharing their workflows here — picked up a few useful ideas.

[xor_]

The AI spam even has a favorite device these days.

(Or is that a requirement for signup?)