回複：複印還是掃描？

It does not matter, as long as it is a COPY. Can be scanned then printed or xeroxed directly. My suggestion is to have a compiled PDF file for all scanned images (passport, I-94s, I-20s, EADs...), so that it is easy to update and generate additional copies (a printer is much easier to locate than a xerox machine). You may scan the documents with full color or gray, then decide to print them in black/white, gray, or color according to the specific need.