Here is a Woodcrafters Series Router Letter Template Set from Vermont American.
Jumbo Letter Router Templates (Clear Acrylic) — Jeff Mack Supply
WoodRiver - Tote Handle Router Template
Woodworking: Make Custom Router Letter Stencils // How -To
Invisible hinges now can be installed easier and faster than ever before. Each router guide template is individually handcrafted for exactness. The template is held on the door and jamb with nails; guide pins locate the deep mortise. The edges of the template assure a perfect outline when used with SOSS RGB100 template guide and lock nut, or the the porter-cable template guide #42024 (Lock face routing) and #42237 (Lock nut).
SOSS 220-IT Invisible Hinge Router Guide Template
Woodworking: Make Custom Router Letter Stencils // How -To
Rockler 4 Interlock Signmaker's Letter Kit
How to Make Wooden Signs With a Router
Letter Router Templates (Clear Acrylic) — Jeff Mack Supply
How to Carve Wood Letters: 2 Simple Methods
Router Letter Template Set
I've gotta cut letters out for a client, would you use jigsaw or
Create custom wood-engraved signs with the Milescraft 1212 SignPro. The self-spacing characters fit into the adjustable clamping system without having to make any measurements. Simply affix the character templates and start routing to create uniformly spaced letters and numbers. This sign making system also includes TurnLock as an integral feature on the BasePlate, and the bushing exchange is tool-free, hardware-free and takes only seconds.
Milescraft SignPro Router Sign Making Jig