The last set of coasters I designed - Citrus Fruit Slice Coaster I gave to my mom and sister and wanted a set for myself. Since I live in New York and it's springtime I opted for a flower design. These are printed in flexible filament (TPU). It won't scratch your furniture and it is super sturdy and durable. They are even dishwasher safe.
I create these designs to encourage people to try out flexible filaments or get some new interesting colors of flexibles. For info on purchasing samples of several brands of flexible filament see flexyfilament.com
To insure a nice looking top surface use 50% infill and extra top and bottom layers.
Some slicers will allow you you pause your print and switch filaments. That's how you get the two color effect. The slicer I use is Cura. Wait until you can make out the petals and a layer of fill - I use a spatula (print removal tool) to catch any oozing.
We developed a great way to distribute cost effective quantities of flexible filament: Splash Spools. A generous amount of filament on a spool with a case so it's not flopping all over the place. Splash Spools store easily in a desk drawer, stacked space or even hang on a wall. Available on www.3dprintNY.com , eBay and Amazon. We stock NinjaFlex, Cheetah, Armadillo, EEL, Filaflex, Flexy2 and Flexy.