This would be a very simple build using the tools taught in previous chapters. So this set of instructions will focus on using a different paradigm of designing. In this build, the Apply button in the modifiers will not be used so that the object remains modifiable until the end. This technique works well for simple shapes but can be a problem when the geometry of the model becomes increasingly complex.
Before opening Blender, some measurements must be gathered. Careful measurements need to be taken of the finger that the ring will be on and of the SD card. A digital caliper is an excellent tool to take measurements with:
My middle finger measures 19.3mm at the widest point. If a digital caliper is not available, another way to measure a finger is to wrap a piece of paper around the finger, mark where it overlaps, and use a ruler to find your finger's circumference. Then consult the next chart to find out the standard ring size and diameter: