The "insert" is the actual mezuzah and it must be handwritten.
The laws of mezuzah are precise and complex. For example, the mezuzah must be written by a knowledgeable, qualified Jewish scribe; it must be written with special ink upon animal parchment set aside expressly for this purpose. Only certain erasures are allowed.
All these conditions and more make a valid mezuzah considerably more expensive than an invalid one. This plus rampant ignorance has opened the mezuzah market to a flood of bogus mezuzahs. A recent study found upwards of 90 percent of all mezuzahs were invalid. Any "Judaica" dealer who sells photocopied "mezuzahs" is either totally ignorant about mezuzahs or is simply dishonest. Either way, any mezuzah he sells, even a handwritten one, is certainly not going to be valid. The only way to get a valid mezuzah is to buy it from a qualified, knowledgeable, God fearing scribe or retailer.
