you might want to rotate the islands with wooden boards so the indentations between the boards run vertically or horizontally. pixels are arranged in rows so you should try and have lines laid out to follow them to prevent jaggy edges. this is probably the cause of the jaggy line seen in your previous image >…
It might not look great but it does what it's supposed to do which is just extending out the pixels outside of the UV-islands. Try scaling down the texture a few times and you'll see that it still looks like it should. There were a plug-in floating around that resulted in nicer looking results where the padding got…