havent had it with janseens, but have had it once with the lefebre dhaenens, and sometimes i get the odd frill, out of them and also once out of two blues locked in there boxes when pairing to prove parentage they raised a mosiac thing lovely looking pigeon raced it and lost it, looked and delved right into the pedigrees right right right back was this mosiac, that was many generations back, wish i kept it for stock in the end