Apple quietly announced, through an alert in the latest update to High Sierra, that they will no longer be offering print products like books, posters, and calendars. They have been offering such services since 2002 in iPhoto. The service will end September 30, which probably corresponds to the release of macOS Mojave.
Many people, myself included, have enjoyed this high-quality, no-nonsense service. It didn’t cost much more to order prints than it did to get film developed before digital photography. And the books and calendars made nice gifts.
However, Photos now supports using third-party extensions to order prints and other photo products through different services. Several companies offer such extensions in the Mac App Store. While these seem to have poor reviews now, with Apple’s service discontinued there may be more of a market for competition that could increase quality.