Clipping mask

[grit]

In PS if you have bottom layer with some shape let's say rectangle, and you create top layer with clipping mask, everything you paint in top layer can't go outside that rectangle in bottom shape.

How to do that in GIMP?

[rich2005]

Gimp uses layer masks https://docs.gimp.org/2.10/en/gimp-layer-mask-add.html and usually you would add a white layer over the background, then add the layer mask from a selection or a channel.

Quote:.. bottom layer with some shape let's say rectangle..

For that particular scenario. Depends on the bottom layer, but sometimes possible duplicate layer, add layer mask (grayscale copy), make layer mask visible, use the threshold tool to get a black/white mask, (edit) color invert, turn layer mask visibility off, select canvas, paint.

example: https://i.imgur.com/LMUttac.jpg Very rarely gets as complicated as this procedure. More usually make white layer mask, make selection, fill selection in the layer mask with black.

Photo shop clipping paths/masks are evil. Often used with a non-standard jpeg used by publishing applications.

If you are into that you can use a tiff file. example: https://wiki.scribus.net/canvas/How_to_I..._text_flow

[Espermaschine]

Gimp has no clipping masks.
Can be substituted with a layermask or even a grouplayermask but is a different thing.

Gimp 2.10 has now a Composite Mode (Clip to backdrop - via the right click menu of a layer) which can act like some sort of clipping mask, but only if the object is on a transparent layer, meaning, the minute you put an opaque layer at the bottom, it stops working.

[rich2005]

Not quite what grit was asking but I can see possibilities.

Keep the composite mode layers in a layer group and add a background outside.

   

Although, since the original has an alpha channel, just as easy to make a mask from that

[grit]

Thank you. I should have put this where clipping masks are explained better
[video=youtube] https://youtu.be/N7XxGr2-4hw?t=111[/video]

[rich2005]

These are the layer dialogue clips from the video.



You are not going to get Gimp working like PS, that has been explained before.

If you use the Gimp Composite Mode -> Clip to Backdrop as Espermaschine indicated,then Gimp works much the same as krita. Layers 2 and 3 in the layer group are in that mode.