Thursday, October 28, 2010

Rutile Colours

Well, turns out there's more to getting a nice soft yellow than just chucking some Rutile into a white glaze!

I thought it would be easy. I've got a bucket of yellow glaze kicking around and all I can really remember about it is that I made it by adding some Rutile to my basic white glaze. Easy, right? But it was a lot darker than what the customer wants, so I thought I'd easily get the right shade by just adding less Rutile. I got a real shock when I opened the kiln, though! The tests were pink! A melon or peach-ish pink, but definitely pink.

Only one thing to do: ask Clayart for help.

Happily, they came through. Several people posted a reply to the effect that Rutile can indeed, in the presence of enough calcium, produce pinks. Others reminded me that Rutile can contain Tin, and that Tin plus Chrome can produce pinks. And yes, the kiln load must have had some chrome vapour in it during the firing, as I had used a dark red Mason stain to paint some maple leaves on a few plates. One person suggested doing a short line blend with Red Iron Oxide.

Here are the results.

Hopefully, if the colour balance is accurate, you can see the pink. The tiles with RIO are, as I expected, shades of brown, with a greenish cast. A little too much like Baby Product #2 for my liking! The tiles with RIO and Rutile are a nice toasty colour, I rather like the darkest one.The last row of tiles, using a small amount of Rutile and varying the RIO are about the closest to what I want. The middle one will probably be what the customer wants.


And, Thank You, Clayart!