I've noticed that sometimes when photographers post castings they use the terms, beautiful , slim, attractive etc.
These are such ambiguous terms and really could do with more definition as one persons observations of beauty and degree of slenderness or attractiveness is not the same for everyone.
I would therefore suggest that photographers be more specific in their description of requirements and have a really good look at some of the wonderful portfolios on this site as you may be missing out on lots of hidden surprises . Be bold and approach a model if you like their look or fit your criteria, they can really only say one of two things yes or no !