Frank: Kevin hit on another criterion that some folks would consider necessary in a "tank" - the weight of the wool.

If you want an indisputable "tank", you may want to have it sewn in heavy-weight wool, ie approximately 15 - 16 oz., or even heavier. For example, the House of Edgar weaves 17 - 18 oz. wool for their line of "Regimental Tartans".

I own "8-yard" kilts in medium-weight (~ 13 oz.) and in heavy-weight (~15 - 16 oz.) tartan. The latter are noticeably heavier - "light tanks" vs. "heavy tanks".

John