Debra, I don't think those are actually enough of a reason to not say something to a person asking for info.
Printers want business, they will quote prices based on the project, so it's not like the first tarot creator has anything to hide - their price paid is their choice to keep hidden, whereas the printer won't be telling us what price the first person paid - the job is always based on estimated costs, same as car repair, every job is different.
Card stock isn't a secret. The choices are offered to the person needing their cards printed, they make the choice as to which to use based on availability and cost. It's not a secret. It's materials available.
If you didn't like working with a company, you can say there were issues, or just that it was not the business work you would recommend. No need to elaborate further. Look at the debate on the Game Crafter discussion.
Any printer that doesn't want to do this kind of work will tell the customer that they no longer do that kind of work. It's not a secret. It's their business to be up front about what they are capable of doing for a customer. The guy I went to told me that they didn't have the equipment to do a spray varnish and that it would take 2 weeks to have the job shipped out and done for that phase once the paper was printed, then would come back to be cut, and quoted the addition on the price that would cover it.
The three tarot creators I talked to all were up front about who they used and what kind of quality work they'd had, even what to pay attention to for minor glitch ups they'd encountered. I don't know of many artists who keep a tight rein on information, most network pretty extensively and will discuss the process or issues right up front. I've found the same with writers, they're up front about who they used for printing and whether they were happy with the results or not.