The images would not necessarily need to be Photoshop files, but they would need to be high-res. To print an 8 x 10" image at a decent 300 dpi resolution would require the image to be at least 2400 x 3000 pixels. The larger the desired print, the larger the original would need to be. Most images in the gallery are (thankfully, for those of us on dial-up!) much smaller than that. :) Happy Holidays!