ANNE a guild member demo-ed what she called a RED DUDE. The red dude is a small scrap of shelf liner which is used under a ruler so it becomes totally non slip. YOU can use it for marking or cutting with a rotary cutter. I was amazed at how well even a small square works to stabilize the ruler. Small scrap even works with big rulers. I was amazed at how cheap it was. Every one got a scrap or two to take with them and there were still more scraps available. I was also amazed I have never heard of or seen this tip before.