Well what with my late post of WIIW (or WIIT) there was only one guess.
Old Kitty guessed: "Algae! LOL!! A pattern on a rug?"
Well those are great guesses, the rug is closer because it is something on fabric.
Back to that in a moment.
Last weekend (as most weekends) we worked on our cottage.
We were quite productive with me doing much of the work and Deb acting in a support role and as budding Photo-Journalist (I keep my good camera and lenses as far away from things like tile glue as possible).
We finished grouting and sealing the bathroom tiles.
Then I began installing a...
And beside that...
Tap (faucet?) fittings for the shower (still have to order a glass shower screen)
and a hand basin
So by the end of the weekend we had this...
Unfortunately, as you might notice there is still light coming up through the floor waste.
We are now waiting on a plumber to connect up the water and drainage (an obligation under NSW law).
We can't wait because we are currently washing everything including ourselves in water we heat on a gas stove!
And traipsing outside to the old "thunderbox" out the back.
AND once the hot water system is connected we can finally light the wood stove and be a whole lot warmer. The bathroom might be coming together but the rest of the house is still very much a building site.
After all that, I flopped in one of our camp chairs where Deb took this piccie of a very exhausted (and grimy) Al.
Finally the answer to WIIW can be found on my left knee...
It's a stain from the waterproof membrane that went under the tiles.