We’re about to build a horizontal wood fence, and I’d prefer not being able to see the fasteners on the face of each plank.
What’s the best way of achieving this?
You can make a fence out of wood that does not show fasteners on one side but there will be fasteners on the other side.
A fence design like this one could work: https://www.diypete.com/how-to-build-a-6-foot-privacy-fence/
With some careful thought you can hide the get all the fasteners on one side.
Take a look at the category known as 'hidden deck fasteners'. It's typically a biscuit slot with a metal or plastic fastener that keys into the slot and then attaches to a post. (Or in the case of a deck, the joist.)
Top tip if you want to save time and wear on the biscuit joiner: have your lumber supplier groove both sides of your planks full length.