Hi Dario
...I think I'm gonna follow this and attach a JPG with every PDF I send.
and then? If both "looks" different on the screen of the customer (because some transparency situations oder overprint mode issues), how you can be for sure that his imprimatur was decided by looking at the "right" one?
I think it´s not a good idea to offer two versions (PDF and JPEG) for one answer (the imprimatur).
The problem for the prepress is, that both versions needs to be explained to the customer:
Regarding to the programm he is looking at the "proof" (@Dov: I think here is more a plott as a blueprint meant with and not first of all a colour-proof...) he must check that his programm is able to respect transparency and overprint by viewing a pdf and if he is looking to a JPEG, he has to be informed, that former vector elements will be print as such...
Also if you will automate the process you will double your work at that point with two versions...
There is simply no solution yet for this dilemma! Not even to insist on a standardized PDF/x-file alone whithout the strongly recommodation of using an Adobe Acrobat Professional or Reader whith activated overprintmode in the presets for all files...
(Therefore it could minimize your sorrows and selfblaming after a failed production to add as an important notice for the customer a manual for dummies how to switch on the overprint mode in Acrobat Reader and to insist on this programm for the imprimatur. Of course, if something went wrong with the production, you will loose the customer in most of the case, no matter who is really to blame, but for a compliant settlement you are in a better situation by this kind of "teaching your customer".)
My 5 cent...
Added: I have met absolutely some customers they liked to be informed about help for getting a more safer way for the imprimatur. Some customers apreciate to get informed about special stuff...
Ulrich