The cover is then lifted and a nameplate made of polyester Perma-Twill is positioned above the number on the back and is covered with a Teflon sheet to protect the rest of the jersey. The cover is held closed for another 20 seconds so the adhesive on the back of the nameplate can stick to the jersey. After the cover is lifted, a plastic strip is peeled off the nameplate.

Image New Era provides each pick at the draft with a cap. Credit... Andrew White for The New York Times

In all, it takes about two minutes to personalize each jersey, which is then folded and handed to a selected fan of that team, who carries it on stage to the commissioner.

Later, Stahls’ will personalize a second jersey that is given to a trading card company that will cut it into little pieces and include them in a set of commemorative cards. Any remaining jerseys are given to the N.F.L., which donates them to charity.

There is, of course, no guarantee that all 30 players at Radio City will be picked in the first round. Geno Smith, expected to be a first-round pick, was drafted by the Jets in the second round last season. Kane said the N.F.L. had not decided how to commemorate an experience that some top-ranked players consider deflating. There is no thought of handing out No. 2 jerseys.

While the first night of the draft is televised in prime time, and many first-round picks are already established stars, the draft does not provide a major boost in jersey sales. The problem is that many teams do not decide for days if not weeks what number their draftees will wear. Sometimes, the numbers the draft picks desire are retired or are worn by another player on the team, and they must negotiate for it.

Fanatics.com, the largest online seller of licensed team gear, said there was a bump in sales of N.F.L. merchandise during draft week, but a more significant spike occurs in August. Still, “we can safely assume that wherever Johnny Football goes, we will be selling jerseys in May,” Kane said, referring to Johnny Manziel.