Ever since I saw jonrgrover's "Heavy Chain", I wondered what forms of Celtic knotwork and chainmail weave could be created on a small grid. This design contains all the ones I have found so far. Feel free to clone this or make suggestions!
All these designs are 1x1 or 2x2; I made larger swatches to show how they tessellate and can form even larger shapes.
If you clone this, I recommend opening another new FontStruction at the same time, then copy-pasting the knots you want from the cloned project over to the new one. This will help reduce the chance that your creation gets corrupted.