RAKU is a very unpredictable medium and is affected by many variables. The effects achieved with these or any other RAKU glazes may not always be the same. Even after you have done RAKU for a long time you will see that it is almost impossible to have complete control over the result or a consistent glaze effect even if you are using the glaze from the same jar. However this is a spontaneous technique and all the varied effects are usually acceptable. Tong marks and other marks from reduction material is considered a characteristic of RAKU, not a defect.