Introducing the Mark Johnson Signature Ceramic Slide February 24, 2017/2 Comments/in Blog, News /by Tom Gray We’re pleased to introduce the Mark Johnson Signature Ceramic Slide, crafted to Mark’s specifications by Doc Sigmier of Rocky Mountain Slides, and available now only through PledgeMusic. Mark’s Signature Ceramic Slide is a custom Shavano in midnight black with a triple color tip. Inner diameter is 19mm. Length is 62mm. It weighs in at about 2.5 ounces.