I first downloaded a .png of a Celtic knot posted by Clker-Free-Vector-Images at https://pixabay.com/vectors/celtic-shield-celtic-design-30081/. I turned this image into a .svg using Inkscape. I extruded this .svg in blender and connected it to a cylinder. I also created the text in blender using the font "Celtic Hand" found at https://www.1001freefonts.com/celtic-hand.font. The words are lyrics to the commonly-sung folk song "Red is the Rose." The full coaster was exported as a .stl from blender and then scaled in FreeSCAD.