8. "Sticks" vs. "Spheres" spacing

Beadrez has two different spacing types. Using the wrong type can cause spacing problems, especially at sharp tips or around sharp bends. You can only pick 1 spacing type per necklace, so pick whichever one looks better at the sharpest part (if you switch types mid-necklace, there is a jump or gap in spacing that you would have to correct manually). If you are mixing both round and tube beads, the "sticks" setting is usually best.

Rezzers and alignment tools do not really guarantee prims "perfectly touching" except for basic cases. This is because perfectly-touching prim placement requires precise information about prim geometry. Rezzers can't access this information for arbitrary prims like sculpties.

Beadrez is the only SL necklace generator to give a choice of spacing types:
sticks (default) optimized for narrow beads like thin tubes, or spheres for round beads like pearls.

The difference is strongest at sharp bends or tips. The first picture below shows how important correct spacing type is at a sharp tip: 



Above: Difference between "spheres" and "sticks" spacing types at a sharp tip. Top row shows what happens with round beads, bottom row shows what happens with tubes. (click to enlarge)

Look at the topmost beads in the pictures below, and notice how accuracy is better with one setting than another, but that the correct setting is different for tubes vs. pearls.
 
Above: Tube-type geometry with default "stick" spacing method

Above: Tube with sphere-type spacing: not quite so perfect at the top

Above: Pearls (actually, snowballs :) with correct sphere-type spacing

Above: Snowball pearls with stick-type spacing : they sink into each other a little bit