10 hours ago
(11 hours ago)Connolly Music Creations Wrote:(11 hours ago)Ofnuts Wrote: If the layer has an alpha channel, erasing is just setting the alpha component to 0, so it's identical to making it transparent (if there is no alpha channel, you get the background color).
If you look around you will see that the recommended method is to use a layer mask, because you can easily unerase
(you paint in black where you want transparency, and just paint over in white where you want to restore opacity). However in recent versions of Gimp the Erase tool has an Anti-erase option activated with that Alt key, so unerasing is just as easy with the eraser .
I'll be uploading a .jpg to work on. Will that have an alpha channel? When do things get an alpha channel?
There is no alpha channel by default when you load a JPG because the JPG format has no support for transparency. You add one with Layer > Transparency > Add alpha channel (and remember to export to a format that supports transparency, so not JPG!, and usually PNG instead).