It's Kreinik blending filament and doesn't show up well in my photo, but adds a nice bling to the page:
You can start to make out the structure of the page now, and the vertical blank spot on the left will be a tree branch, as will some of the blank spot on the upper right. The lower half is almost all blending filament! So it will take a bit. It hasn't been too fiddly, but I'm thinking this is a good couple weeks work to complete just that colour.
Here's the finished piece again so you can compare:
I'm working on the upper right corner currently.
For my weekly rotation I plan on picking up another owl at the end of the week and then going back to this. That way I can maybe catch up on the owl SAL and finish off this challenge. Wish me luck!