Q and Answer: Why does wool get shiny?
Rob asks: Why do wool pants and suits get shiny over time? Is there any way to  prevent/correct this? I remember you mentioned bristle garment brushes  in the past - do they fix this problem?
Wool gets shiny for the same reason anything else does - because its surface becomes smoother.  This is a result of friction from wear, pressing, heat and especially dry cleaning. 
Garment brushes don’t correct this problem, but they do help prevent it.  If you brush your wool tailored clothes after wearing them, they’ll stay cleaner.  That means both less dirt wearing away at the fibers of the clothes and less trips to the dry cleaner.  It’s the intense heat and chemicals used in dry cleaning and commercial pressing that are the number one cause of suit shininess.  That’s why if you buy a suit on Savile Row, you can take it in for a free pressing and cleaning that’s done with a sponge and steam, rather than a big iron maiden-looking super-heated death contraption, which is what you’ll find at the dry cleaner’s plant.
Wool, especially certain weaves, like gabardine, will shine after a lot of wear no matter what you do, but it’s important to dry clean your garments only when they actually need them.  That means a few times a year if you’re wearing them regularly, and once a year or so if you’re not.  If you buy a particularly nice suit, it’s a good idea to get an extra pair of pants - which are typically relatively inexpensive - as the seat and inside thighs are usually the first part of the suit to start shining.

Q and Answer: Why does wool get shiny?

Rob asks: Why do wool pants and suits get shiny over time? Is there any way to prevent/correct this? I remember you mentioned bristle garment brushes in the past - do they fix this problem?

Wool gets shiny for the same reason anything else does - because its surface becomes smoother.  This is a result of friction from wear, pressing, heat and especially dry cleaning. 

Garment brushes don’t correct this problem, but they do help prevent it.  If you brush your wool tailored clothes after wearing them, they’ll stay cleaner.  That means both less dirt wearing away at the fibers of the clothes and less trips to the dry cleaner.  It’s the intense heat and chemicals used in dry cleaning and commercial pressing that are the number one cause of suit shininess.  That’s why if you buy a suit on Savile Row, you can take it in for a free pressing and cleaning that’s done with a sponge and steam, rather than a big iron maiden-looking super-heated death contraption, which is what you’ll find at the dry cleaner’s plant.

Wool, especially certain weaves, like gabardine, will shine after a lot of wear no matter what you do, but it’s important to dry clean your garments only when they actually need them.  That means a few times a year if you’re wearing them regularly, and once a year or so if you’re not.  If you buy a particularly nice suit, it’s a good idea to get an extra pair of pants - which are typically relatively inexpensive - as the seat and inside thighs are usually the first part of the suit to start shining.