Hey all! I'm a long-time lurker, first time poster. I love this place and it has been a wealth of both information and eye candy. I'm a 33-year-old journalist and playwright living in Washington, D.C.

Though I'm not a trad/ivy purist, I'm not a WASP (Irish Catholic, oops.) and I went to NYU (how anti-ivy can you get?), I've always been such a fan of the style for its ease and consistency (Also, I'm a bit of a clothes horse).

With that said, I have a question.

I recently picked up a mid-70s (based on the union label design) Brooks camel hair, glen plaid sport jacket. It's soft shoulder, 3r2 and undarted. I absolutely love it and I picked it up for $8. (Incidentally, a big, floppy Boss jacket from the early '90s was marked $30. There are things in life I'll never understand.)

Now for my question. What makes a sack jacket? Is it purely construction or does it have to do with material? Can a camel hair, glen plaid jacket be considered a sack jacket because of the soft shoulder, 3r2 and undarted construction?

I've read up on the history of the BB No. 1 and all that, but I'm more interested in the sack jacket of the 50s-60s trad style. Thanks in advance for the help. I really love learning about the nuanced histories of the things I love and trad style is right up there with Eugene O'Neill and pre-CBS strats.