Hi Christian,

I just searched on Paph. callosum 'Jack' and I came up with a UK site that sells a very dark vinicolored Paph under that name. Not the same as yours, and also not a Paph. callosum. The retailer you purchased it from probably has no way of knowing the name is incorrect. But a Paph. callosum has downward sweeping petals - usually more than 45 degrees below horlizontal, and yours are horizontal.

This is a photo of a Paph. callosum 'Jac':


Yours is lovely though, and even if the name isn't correct you can still enjoy its beauty!

McJulie