Good news: invitations officially went out yesterday!
Bad news: we had to spend way more than we had anticipated on postage. :-(
After assembling an entire mock invitation, we weighed the invite on a digital home scale - exactly 1.0 ounces. PERFECT! So, we moved forward and assembled everything and had it ready to go. We went to the post office to buy stamps and send the invites on their way. The worker suggested weighing one invite just to be sure because they looked heavy. It turns out that our invitations weighed 1.05 ounces!!!! That meant we had to jump up to the $0.65 postage for each one.
Moral of the story: Don't trust your scale at home. Bring your mock invite to the post office. We could have easily rearranged and cut things down to get down to the 1 ounce mark and we would have saved $0.19 per invitation.
Ending on a positive note: INVITATIONS ARE DONE AND IN THE MAIL! Now time to wait patiently for the RSVPs.