How do I remove or resize the marching ants from around the apple? It appeared when I used the move tool to move the position of the apple. It is in its own layer. I need to modify the image/layer outside that boundary but I am not allowed. I have tried select none. According to the select menu there is nothing selected. I'm a Photoshop user, but I'm trying to learn GIMP in order to teach my programing students how to illustrate games in a software that does not cost an arm & a leg, and is available in Linux.
You can change the layer boundaries size using the
Layer Boundary Size option under the
Layer menu. Thank you @johnpharrell for the right term to search by.
Go to Edit -> Preferences -> Image Windows -> Appearance and untick "show layer boundary". Then you have to restart Gimp to make the changes.
That link may be helpful to you also. All the best.