Printables can be anything that (yes, I am going to say it!) you can print.
Think contract templates if you are in the legal field, weekly planners, bullet journal templates, checklists, cheat sheets, low-resolution prints, blueprints, diagrams, the list goes on!
For a complete list of inspiration visit https://www.pinterest.com/explore/printables/?lp=true
Just as we mentioned for photography, maybe you provide your product as free printable for personal use, but request price point for commercial use or higher resolution version?
Maybe (getting crazy here!) your printables are offered for free but you have a Shopify website for t-shirts, mugs and high-quality framed prints?
The point is, while it might be possible to set a price point for your printables (i.e. legal contracts or custom templates), most often we see printables used as a lead magnet (free giveaway in return for email address) which tease users and prospects to purchase a higher price product or service (i.e. online course or coaching package).
For example, Nanci gives away several printable (PDF) guides, checklists, cheat sheets on her website, which, while providing a solution to her prospects, serve as marketing for her online course, Zero to Portfolio, An Investing MasterClass.
Bottom line: How can you use printables as either an item for sale or a (free) lead magnet that could entice users to look at your higher priced products or services?