Waveshifting fibers are embedded into the scintillator, then collected into two bundels that will attach to phototubes.
The scintillator is wrapped in white Tetratec to contain light.
The fiber bundles are wrapped in opaque material.
The tile and fibers are wrapped in opaque material, and the fibers are trimmed at the connector to the phottube.
Images courtesy of Alex Moiseev.