Different brands of clay have a different feel right out of the package. Some clays are fairly hard feeling, some are quite soft. Regardless of how they feel right out of the package it is important to condition. As a general rule of thumb, the amount of manipulation to condition is gauged by the amount of manipulation it takes to blend two different colors into one color. Conditioning can be achieved by hand, or using a pasta machine.
The first Fimo Classic clay I purchased I ended up cutting it into small bits, then placing it in a pulsing small food chopper with some Quick Mix. Although more difficult to condition than soft clays, it enjoys a reputation as an excellent clay to cane with.
Fimo Soft clay, is much easier to condition.
Cernit clay was easy for me to condition right out of the package, running slices through a pasta machine. If hand conditioning, just remember the two colors into one rule.
The same was true of Premo Clay.
I’ve used a conditioning tip by Mike Wasmer for Kato Clay, and that is using a rubber mallet and my basement floor! Kato clay likes to be compressed even before running through the pasta machine and the rubber mallet works well for me. I do sandwich the clay between sheets of plastic deli wrap to keep it clean. After several times folding a pounded ‘pancake’ in half and re-pounding it conditions up nicely. If you choose to condition in this manner take care to pound from the folded edge outwards, to avoid air pockets being trapped in the clay!
However you condition, try to avoid trapping air in the clay. Trapped air will become a problem for you, so best to avoid. ; When running clay through a pasta machine, place it folded edge into the rollers, or the folded edge to one side, so air has a path of escape. If you do have air pockets in clay, (they will be visible as bumps on the surface of the clay) pierce them, compress the clay with fingers to push the air out, and/or roll through a pasta machine from the thickest setting to a much thinner setting. The carefully fold and roll through to a wider setting. Air trapped in a bead can lead to cracked beads – or any other polymer clay item.
Especially while caning, it is desirable to have all clay colors used be the same consistency. Even among brands I’ve not found all colors to be created equally! If polymer clay is too soft and pliable, it can be rolled out and placed between two layers of unprinted paper. Left overnight, the clay will absorb some of the plasticiser. If the clay is too stiff, there are products available to help soften it. I personally add some translucent clay of the same brand. Translucent clays seem to be the softest of the clays offered by all the manufacturers.