"Wool socks" and "napkins" are unlikely to get you birked by a nervous/spooked officer if he happens to see them.
To the OP, IMHO it would depend on many things. What you're carrying, your method of carry, where the gun actually is at the time, where you keep your paperwork, why you're being stopped, etc. Depending on the unique circumstances, and LE agency, it *MAY* be *PRUDENT* to inform the officer. While there is NO LEGAL REQUIREMENT to do so in WA state, traffic stops have different "rules" (both perceived and written) vs just walking down the street. In our one and only encounter with the police, when my wife got pulled over a while back, she informed the trooper that we were both carrying. By his reaction, she could have said "wool socks" or "napkins." She even had to go into her purse, where her gun was, to get her license, and said as much. Trooper was fine with it. But, this was the WSP who have a reputation of being more level headed with armed citizens. If you're riding a motorcycle in a T shirt & shorts (dumb idea in the first place but legal) with a gun on your hip that sticks out like a sore thumb, probably no need to say anything since it's plainly obvious (and probably the reason you're being stopped in the first place, which is another thread...). If your carrying concealed & have to put your hands any where near where the gun is to get to your wallet, etc, probably wise to say something.
Now, you could also try the tactic some here advocate of only opening your window a crack to pass paperwork thru and generally being
"snotty," but good luck getting off with just a warning if you pull that. Which also can't be done on a motorcycle.
It also REEEEEAAALLLY HELPS to avoid giving them a reason to pull you over IN THE FIRST PLACE by simply FOLLOWING THE DAMN TRAFFIC LAWS WHETHER YOU AGREE WITH THEM OR NOT and making sure your plates & tabs are in order, whether you agree with them or not. I may hate the helmet law, but I'm not going to intentionally flout it and make myself a target.