Scl stamps are 4 cm (1.5 inches) in diameter. MKM stamps are beautifully carved, have unique designs, and release well from clay or any soft medium. MKM stamps are made from wood that is precision carved to make deep beautiful impressions. The stamps are also bevel carved, allowing them to release easily from clay. The Scl stamps are finished with tung oil to ensure durability over many years of use. MKM stamps are easily cleaned with water and a soft toothbrush. All MKM stamps, rollers, HandRollers, Mini Rollers, etc, are carved at our own factory (they are not contracted out to second parties) by MKM employees who are very committed to quality. Quality in the original wood blank material, quality of design, and quality of carving, quality of wood finish (teng oil), and, of course, quality service to all of our customers. But what, exactly, does quality mean in the context of a simple wood tool. At the design level, it is a bit of a personal choice. A design that you like is a good one. But at the carving stage, the meaning is very specific: the edges of the debossed (cut-in) stamps all have bevels that compress the clay around the stamp and prevent cracks at the corners. Indeed, none of the lines and patterns cut into the stamps and rollers are laser cut (which always leaves a burned vertical wall, which then pulls up the edge of the design.) All MKM stamps are cut with cutting blades that leave a bevel for all the lines and patterns. So when the MKM stamp pulls away from the clay, or the roller is rolled over the clay, the MKM tool releases perfectly without pulling up any edges. As well, our stamps and rollers are scaled to work well in the realm of functional pottery – these tools are not re-purposed paint rollers – they are designed and made specifically for the clay worker. The wood that we use for our rollers (RS, RM, RL, HandRollers, etc) is fine grained and carved very precisely. This wood is leftover from the furniture industry and is ‘recycled‘ by MKM to make our small tools. It also takes the tung oil well. And why pure tung oil, which is expensive. Because it is one of only two naturally occurring oils that are self-polymerizing(that harden when exposed to the atmosphere). This means that these tools will be much more durable over time than tools that are bare wood or finished with other oils.