Chicken eggs which have washed in the machines for commercial use sometimes get scarred as they roll around hundreds of times on the belts that move them and that makes the pysanka dyes take unevenly.
So I went to google and asked “how are eggs washed commercially” and what came up, I read, and wasn’t really happy about what things were mentioned. I recommend that anyone who eats eggs, go to the website at the bottom of this page. So from this I suspect that the reason for the unusual dying qualities of commercially produced (meaning chicken mega-farms (hear this!! there are 60 chicken farms that have 5 million hens each… how do they keep them clean and healthy). Washing eggs is not good for eggs, but when they are washed there are very definite do’s and don’ts. I will need to google Kroger eggs to see what they do to their chickens, chicks, and eggs. Anyway, here is a pysanka made from a Kroger egg.
http://articles.mercola.com/sites/articles/archive/2010/06/08/why-you-dont-want-to-buy-organic-eggs-at-the-grocery-store.aspx