 Batman reveals to Tim that he had doubts about her death, which is why there was never a memorial of her in the Batcave, and implying that Batman begins doubting at some points after his confrontation with Leslie and thus didn't alert the authorities.Traffolyte

Traffolyte, sometimes spelled Traffolite, was a brand name for multi-layered phenolic plastic sheets suitable for engraving.Each layer was a different colour so engraved letters or shapes would be a different colour from the unengraved portions.