Thanks so much, Paul and GW!

So I did check the file for the t-shirt design, and sure enough, it is less than 3000 pixels (but not by much). That probably happened when I was trying to get the files via email to my partner - I had to reduce them to get them to send. So I've resized the tee design using PS4 with no problems. But when I try to resize another design for our project - this design is for a hat - something weird happens. The file is pretty big, and I'm trying to reduce it to 3.5"x2.5". But PS4 isn't cooperating. So I'd like to try to resize that one using Xara. Can you tell me how to do that? After resizing the 2 designs, I'm going to try to get them to my partner using PDF/X per GW's suggestion and Drop Box. Thanks again, guys, for your advice!