The channel is routed directly into the face of the solid hardwood shelf before finishing. You specify the position, depth, and width; I cut it to those dimensions. There's no standard channel location because every LED setup is different, and a channel in the wrong position defeats the purpose.
Position options:
Up lighting routes the channel on the top face of the shelf, set back from the front edge. Light projects upward and washes the wall above the shelf, which works well for accent lighting, highlighting art or objects displayed above, or adding ambient light to a room without a visible light source.
Down lighting routes the channel on the bottom face of the shelf. Light projects downward onto the surface below, which suits task lighting applications in kitchens and bars, or creates a floating effect where the shelf appears to glow from underneath.
Both is possible on the same shelf. Specify two channels, one on top and one on the bottom, with your dimensions for each.
Custom positioning is available for any other configuration. If you need the channel at a specific distance from the front edge, back edge, or positioned for a particular diffuser profile, include those dimensions in your order and I'll route accordingly.
The one constraint: channel placement needs to stay at least 1.5" from the back edge of the shelf and 1" from each side. Everything within those boundaries is open.
For more info, read our post Light It Up: How to Add LED Lighting to Your Floating Shelves