Hi
@danielacfield
In most cases for T-shirt prints, one wants the surrounding background made transparent so only the subject of the image is printed and the background is just the T-hirt by itself with no added printing. My response below will address how to do that yet your description is lacking details so you may want something else. If that is the case please clarify.
- First load the image into PS. I used a bird with a background
In the Layers Panel, click on the lock symbol to delete and this allows there to be transparent backgrounds
Now you want to make a selection for the background. There is many ways to do this. On more recent versions of PS I have used the Select > Subject command.
To change that selection to be the background it just needs to be inverted. That is done with the command Select > Inverse or the keyboard shortcut Shift + Cmd+ I (Shift+Ctrl+I on PC)
Now just click the delete key (backspace on PC) to delete the selected background. I also used the keyboard shortcut Cmd+D (Ctrl+D on a PC) to remove the selection (so not marching ants)
From here, you can crop your image to the desired size and then save as a PNG file with the Transparency Box checked to save the transparency with the file. Save the file and use that to print your T-shirt
Hope this helps
John Wheeler