So I've just finished reading Way Beyond Monochrome, and the things that blew me away most by a long shot were not split grade printing, but the results demonstrated from using unsharp, SCIM, fog and highlight masks. Pin registering small (120) film with masks using actual pushpins and foam ore would be straightforward, but my big concern would be how to register a glass carrier in an off-the-shelf MF enlarger so that multiple, mask on, mask off carrier insertions would be perfectly repeatable. Anyone done this with common enlarger brands? Your advice/insight would be appreciated.