San Francisco 49ers Chalk Line crewneck

✓Read the tag first: maker, country of origin and fiber content. A Made in USA tag fits the 80s and early 90s better than the 2000s.

✓Match the graphics to the team's timeline. The logo, colors and city name should all fit the era the seller claims.

✓Look at the print. Light cracking is normal on an old screen print, but peeling, missing sections or a print that looks brand new on a worn shirt deserve a question.

✓Ask for pit-to-pit and length measurements. Tag sizes vary by maker and era, and cotton-heavy fleece can shrink.

✓Check the cuffs, waistband and collar ribbing for stretch-out, and the underarms and hem for holes, stains and pilling.

✓For Reverse Weave, look for the side panels and Champion labeling. The fabric runs crosswise, which is how it resists shrinking in length.

✓Rule out reissues. Mitchell & Ness and other retro lines, plus the league's own throwback collections since 1991, put old designs on newer garments. A web address on the tag means it is from the internet era.