Dust cover up or down?

I think with a fully suspended table like a Linn LP12 the dustcover is less likely to color the sound, but with a non-decoupled plinth it’s much better without the cover or at least with cover up. I have seen the static attraction effect at work myself so that’s another reason to go up or off. My WTT/TA has an unhinged “cake cover” so it gets removed for playing every time. I once had a Technics SP12 with a heavy rubber plinth and the dustcover really degraded its sound quality when down. 

It is inconceivable to me not to have a dust cover. Seems absurd to leave a tonearm with super-fine manufacturing tolerances, precise movement subject to dust or any airborne substance, often invisible when not in use. Irresponsible of OEM's not to provide them IMO.

Owning a Rega P8 takes this decision away.

• Dust cover on when not in use
• Dust cover off when in use

Prior turntables I took the dust cover off because my older brother told me to.

Depends whether the dust cover has been cryo treated or not. Zap with your Zerostat just to make sure. Use a green marker around the edge of the cover for extra protection. I just use a dirty old handkerchief that has to be taken off before I start up the platter.

This question reminds me of a previous statement. "I keep a Polka Greatest Hits" LP on the TT when not in use.  It's great for keeping dust off the platter. 🤣