I've always noticed that eggs that are maternally incubated seem to never really stay full for very long, so I aim for that. I'm currently doing substrate-less incubation using moist cypress mulch, instead of a traditional media, and the eggs dimple quickly and stay that way. Within two weeks the eggs looked as deflated as eggs looked last year on day 50. I've noticed that the eggs are whiter and cleaner looking (today is day 49 for my first clutch), and the eggs are just as white as the day they were laid.

Last year by this time, using perlite (substrate-less) and keeping the humidity at 99% to 100%, the eggs had started yellowing a little. I haven't bothered to check the humidity, but I don't get any condensation anywhere in the box like I did last year. I'm incubating at 89.8 - 90.0, and will be cutting the first clutch on Tuesday (day 55). I want to see if this method will effect the hatch times or birth weights, but so far I'd say the eggs are looking a lot better with the mulch and less humidity than they did when I kept the humidity high enough to keep the eggs plump.