Dependant on the solution if I remember from my fathers teachings more than 30 years ago a solution made up of coppersulfate pentahydrate as the catalyst with copper anode approxiamately 15 v dc but don't remember current per area will try and dig out his text.
I can say that noemal acidic or alkacalyn copper electroplating is not possible for such a thickness. You mat try electroless copper or copper sulphamate bath. I have been used it for electro deposition for molds. Electroless copper plating also gives hardness to the copper layer. Hope this would help.
Thats fantastic. I think you didnt use any brightener. Just a very good wetting agent and a special leveling agent. I have tried a lot but could not succide. You should use a very low current density but this time deposition become very low and takes a long time. In any was in my trying after 10-20 micron surface become very bad.
If you are able to give more information about how you did, I would be very glad.
I have electroformed copper components up to 10mm thick on SS using standard acid copper sulphate bath. So 1mm thickness is no problem. However adhesion may be poor.
Unless the end use is known it is not possible to give a meaningful answer.