Another potential source of images for your inspiration and engraving fun has gone public.
Students, educators, and just regular art lovers might be interested to learn that we’ve released thousands of images in the public domain on the new website in an open-access format (52,438 to be exact, and growing regularly). Made available under the Creative Commons Zero (CC0) license, these images can be downloaded for free on the artwork pages.
My favorite museum site for high quality images is the Riijks Museum in Amsterdam. Think Rembrandt and Vermeer. Drawings and etchings are also available. Almost all of their collection is on-line and they encourage designers and artists to use the images.
Convert to svg still faster and easier than the raster manipulating to get the same effect, provided everything can keep up with it. The vector is easier to clean up and manipulate after, at least sometimes.