"All firearm sales or transfers, in whole or part in this state including without limitation a sale or transfer where either the purchaser or seller or transferee or transferor is in Washington, shall be subject to background checks unless specifically exempted by state or federal law. -- New section RCW 9.41.113 (1)"
The key word in that section is transfer. Normally, if I was selling a firearm, I would expect the transfer to occur when I exchanged the firearm for money. If I was just handing my firearm over to someone else to look at and hand back to me, I wouldn't consider that a transfer.
This is not so in Washington state anymore. Initiative 594 caused the state definition to change: "'Transfer' means the intended delivery of a firearm to another person without consideration of payment or promise of payment including, but not limited to, gifts and loans.' -- RCW 9.41.010, section (25)"
If someone else merely handles your firearm in Washington state, you are both guilty of a misdemeanor or felony (see RCW 9.41.115). The clear intent of I-594 is to impede common interest in firearms through trickery.
I-594 treats more than one subject; I-594 violated the single subject rule, and thus the election result on I-594 is invalidated by sloppy initiative writing. Washington State requires clarity. Had the People really known what they were voting for, there is no doubt the result would have been different.
Our state's firearms laws used to be based on the principle that individual people have the right to run their own lives. Now, personal "rights" are subject to review and permission from a bureaucracy. That sort of filter would catch criminals, but by definition criminals don't obey the law. No bureaucracy is perfect, so only the law-abiding will be "caught" and found guilty of crime.
There are more subtle changes than just those mentioned above. Please protect yourself from the spider's web. Download and study a copy of the entire state firearms regulations. Then write your state legislator and demand action on removing I-594.