I'm interetsted in knowing how you make be addressing the Certification for Testing of Merchandise under the Consumer Product Safety Act of 2008. More specifically, are you obtaining certficates with each shipment and are you using a standard form?
You do need to use a specific form. Each company can make their own, but the form must follow standard requirements regarding what information goes on the form. As far as I can tell, the government has not yet provided an actual form to use, but they did provide information on what goes on the form (they list this on the consumer products safety commission site).
As per my understanding, you need a CPSIA form for each shipment. However, the form does not have to physically go with each shipment. As long as the form is accessible electronically (online), it would be considered to be with the shipment.
I have created a page regarding CPSIA at Apparel Search. You an check it out at CPSIA.