Just using Alt doesn't do anything in Krita?

[z01ks]

Ctrl is color picking. Shift is brush size. Space is panning. Does simply pressing Alt do anything in Krita? And if not, why… not?

Also, I was curious how other users use the Alt key in Krita, so please share your way of using this key.

[sooz]

The alt key is used by Krita’s selection tools.

Pressing the alt key while using a selection tool sets the subsequent selection to subtract mode.

Shift+alt sets it to intersect mode.

[z01ks]

We need more use out of Alt. It resides in such prime real estate on the keyboard.

[mmiller]

When creating a rectangular or elliptical selection, the ALT key comes in handy. While you are creating a selection, press ALT to drag the selection to another location. Once you have done this, you can continue creating the selection in any way you want (with SHIFT pressed for a perfect circle, for example)
(translated with goog. translator)

[Takiro]

ALT key is used as a modifier for many tools to invoke alternative behavior. ALT on it’s own doesn’t do much but in combination with other shortcuts it does.

[AhabGreybeard]

Whether you press-hold Alt (and the other modifier keys) before initial click/touch or after initial click/touch while using the rectangle/ellipse shape/selection tools affects the action.
It’s a good idea to experiment at first to see the various different effects.

The Alt key can be used on its own combined with mouse button operation in the Canvas Input settings for use while painting on the canvas.
I think some people like to use Alt as the canvas colour picker.

[Rakurri]

Oh and also one can use it for quickly navigating menus!
Do you see those lines under the letters in the menu? For instance the “Settings” menu has the “n” underlined. If you hold alt + N you will open that menu. In that menu, “Configure Krita” has “C” underlined and so on.
Holding Alt and pressing N + C + W will be the shortcut for opening the Window settings
I basically never use this feature but it’s kinda cool

[sooz]

Good point, @Rakurri. I always forget about alt+menu item letter. That one is so standard and so important I think I use unconsciously.

[sooz]

@z01ks There is another fabulous use of the alt key from @mmiller in the tips and tricks thread:

Tips and Tricks - Hidden Gems in Krita

one more You have the brush tool, so you press CTRL for the eyedropper tool shortcut, you hold down CTRL and press ALT at the same time, then the magic happens. You are on a layer with 50% opacity, but you want the original color (at 100%) with ALT you catch the original color. (translated by google translator)

[Takiro]

That’s not only a Krita feature but a common feature in all applications since at least Windows 3. So common that most GUI frameworks have it built in already by default.