There's a new section on Kenrick-Glennon Seminary's website which includes many high-resolution, copyright-free scans of religious and biblical etchings, from many different sources. You can browse through all the pictures and download the original high-res scans to use for anything you'd like!
There's also a section with an online version of the Holy Way of the Cross, with beautiful etchings and meaningful reflections on all fourteen stations, which you can browse online whenever you'd like.