The typical premium grass seed mixture offered by higher end nurseries is packaged as “PNW Mix” and includes Fine Fescue, Perennial Ryegrass and sometimes a small percentage by weight of Kentucky Bluegrass. As I mentioned, the KBG will be outcompeted and doesn’t do well under normal Western Washington conditions.
I’ve been using a Fine Fescue Blend for many years sourced from Seed Research of Oregon. This is getting more difficult now that SRO has been acquired and has transitioned to Seed Research by DLF.
I have been considering backing off of maintaining a Fine Fescue Blend and transitioning to a Perennial Ryegrass/ Fine Fescue Mix. An SRO Mix I was considering was called;
Champion® Fine perennial ryegrass and SR 5130 Chewings fescue mixture.
Certified mixture of 70–90%
Champion® GQ perennial ryegrass blend and 10–30%
SR 5130 Chewings fescue.
Champion Turfgrass Mix offers durable turf for athletic fields, featuring GLS tolerance and quick establishment for lasting performance.
us.dlf.com
SR 5130 strong creeping red fescue thrives in sun and shade, high or low maintenance, offers insect protection, disease resistance, and stress tolerance. Ideal for blending.
us.dlf.com
I’m not sure of availability or if it goes under the same name but that is what I was planning to use if I decided to transition, which I keep kicking down the road. I currently use SR 5130 Chewings and Ruddy Strong Creeping Red. I assume there are other quality options from other growers, just try and get "no weed" certified and a PR/FF mix should serve you well. Good luck.