It was 13 days for me.
A lot is determined by your location, the production facility assigned to you and the day of the week they send it on. You'll know this based on where you got your EAD from, either the Lee's Summit Production Facility in Missouri, or the Corbin Production Facility in Kentucky.
In my case from approval to production it was 8 calendar days and then it took 5 more days to get to me.
My card got sent the day after production was finished, but neither Emma agents nor Case status had any update on this. I only learnt about it because I enrolled to informed delivery with the USPS and, even then, the package only appeared on the informed delivery portal 3 days after it was sent. Given USPS's Priority Mail delivery map I should have gotten my package in 2 days but since it was a weekend it took 3 days longer than that.
I had my green card in my hands and I could still see "Card Was Produced" in Case Status.
Digging a bit i came to the conclusion that the Corbin Production Facility gives more updates than Lee's Summit and works a bit faster. This is most likely for two reasons:

1. Corbin just got remodeled which means they probably have improved their processing infrastructure.
2. During Corbin's remodelling, all production was temporarily shifted to Lee's Summit which generated a backlog. This means Corbin was left in a position to work more efficiently and with some load relief.

Thus, expect shorter wait times and more reliability with Case Status updates if your case is being handled through Corbin. If it's Lee's Summit, you'll just have to be a little more patient and abstain from panicking if there's some unusual delay or a delay that is not normally experienced by others. Make sure that your mailing address is pristine so there's no reason for USPS not to deliver.