Cutting or Trimming a Background Title

This is my first time posting in the forums, and I was wondering if there was a way to use the tools at hand to trim or cut away from a tile? Say I have a large tile of grass that I'd like to put in the middle of the ocean to make an island. I obviously don't want just a big undefined square. I'm not sure if I'm just blind/dumb, but is there any tool or combination of tools that would allow me to trim the layer of grass and make it have a more coastal shape?

you could probably just the in roll20 image search and find a decent looking island though. or find something on google images. The gold standard is a .png ... because they have a built in transparency so you can slap multiple images on top of each other.

If your ocean doesn't have any texture but just a plain color then you could try dropping the grass square on to the map layer then use the drawing tools to draw over it so that you cover parts of it. It probably won't look that good but that is one way. To expand on Kristin statement, to do it proper justice you would need to use a third party photo software like gimp or photoshop or something similar so that you can edit the grass. This will allow you to shape and trim it to what you want then you can drop it on to your map.

Right-o, thanks for the help guys. For my first forum post I'm impressed with the response time and quality of the replies. I have gimp so I'll go ahead and give that a shot, though I'm a bit rusty at image editing. One last question for any who can answer, is there a more accurate way to move placed images after they've been placed on the campaign page? For example, when I select an image/element, boxes appear on the corners as if I could drag them or interact with them in general, but if I left-click I just place another image. Any help for that issue?

That sounds odd, Jimmy; those boxes do indeed allow you to resize the image (and the box sticking off from one side lets you rotate), while simply dragging the image around lets you move it. You say when you left click you get a second copy of the image? Are you holding any keys down when that happens?

Those boxes are there while it is on the token level but I think they go away when you right click and chose to send it to the map level. The additional images sound like a glitch but I could be wrong.

Just before I received your replies, I had noticed that I was switching tools from background to Token layers, and I kept replacing the same token down, while trying to edit the background layer. Thank you guys again so much. I got it figured out now.

Good to hear and if you need help then just post so that people can help you.