No such! You get a bag of say...7cm white rounds and they can be anything from about 6.6 to 7.4, various subtle variations in lustre and colour...phrrrrrrk colour, overtone. Buttons you say - some deep, some shallow on top of everything else. The most challenging are the baroques - drops and ripples and the ones I call splats, the freeforms which look like you threw something down and it went splatt
It's a hard job but...etc