I struggle with pencil coloring and any successes take hours. I had the luxury of an artist friend showing me a few tricks. The first is that Prismas are now made in Mexico which is why they break all the time no matter how careful you are even though they blend well. I've tried other brands and love all of them much better and not one single one broke while sharpening. Secondly she never uses gamsol or mineral spirits. She blended simply by layering color and it does work but is time consuming. The more pencil you lay down the better it blends working slowly with light colors first. On a snowman for example she colored the entire snowman in white for the first layer. Other brands such as Caran d'Arch are fabulous and blend easier with less layers. Again I still struggle but her helpful hints did make it a bit easier although not fast.