I have tried some different methods for conditioning Kato clay and here are my findings.
As I would Fimo
With Fimo and Premo you can just squash up a bit of clay and roll it through the pasta machine. The odd block of Fimo would be a bit more of a challenge and would need a bit of squishing and rolling in your hands first before it was soft enough to be rolled in the pasta machine.
This doesn't work for Kato, it is too firm for me to squish into a ball from the packet and many blocks just fall into crumbs the minute you try.
I found out about this from Sue on Cindy Leitz's blog, she passed on the information given on an Australian clay suppliers website Over the Rainbow.
Cut a bit of clay and roll it firmly to flatten the clay. Lift it and turn it so it doesn't stick to your work surface. Keep rolling until it is just a little thicker than the thickest setting on your pasta machine (that's a good time to get those thickness chips out to see how
thick it needs to be).Roll the clay through the pasta machine on it's thickest setting. Without folding or bending the sheet roll it through a thinner setting. And again without folding another thinner setting, the aim is to make a thin sheet as thin clay conditions faster. When you have thin sheet fold it and roll it and continue doing so until it is conditioned.
This works but it is slow and I am impatient. Each slice is small and if you are using big amounts of clay it takes far too long. The secret I worked out at last is the initially rolling. If the clay is crumbly roll it more with the rolling pin first or you get crumbles in the pasta machine as shown (I hate that!). I try to short cut putting several sheets together but I think it is best to have them part conditioned first on reflection before bulking up. This is also basically the method recommended by Donna Kato herself and she should know!
I bought a little chopper just for clay. I found I could put about 2oz of clay in at a time without stressing the motor (getting horrible grinding noises) as long as I chopped them into pieces about 2x1x1cm. Run the chopper in bursts until the clay is lots of fine pieces. I then find it easiest to put the clay crumbs into a Ziploc bag and then roll them with a rolling pin in the bag. This helps the crumbs to stick together with no fear of loosing them. The clay is nice and warmed up by now and should go through the pasta machine no problem. A couple of rolls and it is ready to use.
To be honest this is a fair bit of hassle too. It's great if you are colour mixing from a recipe as you can just put the parts in the chopper and it is more than half mixed already. I am buying big blocks of Kato the 12.5oz ones so will probably have a conditioning session at the start of a project using the chopper and then store the clay in sheets. They can easily be reconditioned by passing through the pasta machine.
The bottom picture shows what it looks like out of the Ziploc bag on the left and after first pass through the pasta machine on the right.
This is the method used by Jana Roberts Benzon. Basically you take your block of clay and whack it. Leave the clay in the wrapper and whack it with a hammer, rubber mallet, wooden rolling pin. Works pretty well and is a good arm exercise, tension reliever. Not ideal with those who have problems with hands/arms and it means getting stuff not in my clay kit out. You still have to do a bit of rolling to get it thin enough to go in pasta machine but no crumbs in sight!
(more info in an article at Polymer Clay Express )
Since I wrote this I have found that if I am colour mixing a fair amount of clay I use the chopper but other than that I tend to use the slice method cause as long as I roll well to start with crumbs are avoided and it saves getting extra kit out. I am using the big blocks of Kato so I do 1/4 block at a time - about 3 oz. This would be 3 slices so it isn't so bad.
Anyone else got any conditioning tips to share? I have heard people talk about driving over it with their car but that's a bit extreme for me I think!