VectorClip3D offers hundreds of amazing 3D relief Clipart designed specifically for ArtCAM Express (a copy of the software is required). The original Clipart they have available, which is being updated daily, ranges from borders, plates, historic people, sports, landscapes, and just about anything else you can think of. And if you can't seem to find the Clipart you are looking for, they also offer custom-designed 3D Clipart, for your business or simply for personal use.
They have several FREE 3D images for you to download and try out on your General CNC machine. You can also sign up below for a 30-Day (10 download limit) trial subscription to their website. They offer access to their full portfolio of Clipart for one annual fee.