Question

英语长句结构翻译以及分析

Structured magnetics specialist TSSI has launched OptiGard, a food grade hologram on the back of which a special coating adds a covert machine readable, permanent magnetic signature that provides yes/no authentication.

关键是那个WHICH不知道指代哪个啊？请高手指点迷津。谢谢！
整体意思，看谁能翻译得顺畅些。。。

Answer 1

不错which是关系代词引导了定语从句修饰a food grade hologram，具体说来which指代的是hologram（全息图）

Answer 2

a food grade hologram