there was a website which looked very much like bitaddress.org and did exactly what you wan: create paper wallet for many altcoins: here is the link:
https://walletgenerator.net/ it supports 150 cryptocurrenices already.
this is not a feedback on its safety though. i am just mentioning that it exists. you have to judge if it is safe to use it or not.
also remember that when you create a paper wallet you need to spend it some time. and for that you eventually have to install the original wallet and waste a lot of time syncing with the network.