F1 First Generation Designer Breed
100% Purebred with a 100% Purebred bred together to make a perfect 50/50 mixed puppy
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F1b Second Generation Designer Breed
100% Purebred with a Designer Breed (50/50 mix) creates a puppy that is 75% of one purebred and 25% of the other purebred. Still a designer breed consisting of only two purebreds but will carry more traits from the one breed over the other.