I am working to make a border for a GIF. May I ask please how to enable the stroke selection for a new layer in GIMP?
As far as I can tell from your screen shot, you haven't made a selection. Stroke selection will be greyed out if you don't have a selection.
The yellowish dotted line around your image is not a selection, it's only the layer boundary.
A selection looks different from the layer boundary, it has a "marching ants" animated effect, and is not yellowish.
You can switch off the layer boundary if it's confusing you. Click View in the main menu, and deselect the Show Layer Boundary option.
If you want to select the entire image hit Ctrl+A(Select all). Now you can stroke it using Stroke Selection.
thank you for your help. It is GIF file May I ask please if it is also true for GIF file? I would like to add a border in a GIF file.– ManghudNov 30, 2020 at 11:21
If you want to add a border to an animated GIF, then you'd have to add it on every frame of the animation, which could be a bit tedious. I'm unfamiliar with the GIMP FAnim Timeline plugin you are using, but if it's anything like Photoshop's timeline, then you could just add the border to a new transparent layer, and use the timeline plugin to add it to each frame (this is just a guess, so don't hold me to it). Nov 30, 2020 at 11:26
you can take you selection and left click it in the layer tab, select 'alpha to selection, then in the path tool, add a new path layer, and at the bottom use the 'selection to path' icon. Then stroke path.