BIFL shoutout to Excel #11 blades. I bought this pack 15 years ago and it's still going strong with 27 left. Way sharper and more durable than Xacto. : r/BuyItForLife
Excel K18 Grip-On Knife with Safety Cap (#11 Blade) Colour Black
5pc Excel No 11 Double Honed Angled Knife Blades
Excel Blades #11 Double Honed Blades | Utrecht Art Supplies