In Adobe Photoshop CC 2015, I am opening an image (File > Open > Image), and when it opens, it isn't as a locked Background layer. It opens as Layer 0. How can I make my image open as the Background layer?
The image contains transparency.
Photoshop honors the transparency and opens it as
You can't make Photoshop "open it as a background layer" because then Photoshop would be altering the image as it's opened, and apps just don't do that.
If you want a
Background Layer you need to flatten the transparency. Simply choose
Flatten Image From the Layers Panel Menu
Be aware... you'll get a background color which matches the current background color you have set and you'll lose all transparency in the image.