CHOP is silent about the number of bid copies. 
 
There is no correct answer to this question. It depends on the client, the project management company and yourself. For most purposes, a single original may be sufficient and photocopies will be accurate enough for reference or mark-up. Note that the embossed images of some corporate seals are not picked up well by photocopiers. Shading the embossing with the side of a pencil lead can significantly improve the detail of a photocopy.
 
The number of original copies required should be kept to a minimum. The time of bid closing is hectic enough without adding to it with a requirement to submit multiple originals. There is a greater chance of transcription or other errors as the number of originals required increases.
 
One original to be initialed and kept for record purposes may be enough. The bid receiving authority or other party can make copies of the bids once they are opened and initialed.