I have been refining my method on making these and I figured I'd share a few tips that have helped with my precision. Precision is key on these. Anywhere you are not precise ,will result in a gap. The initial squares need to all be the exact same thickness and they need to be exactly square. Rectangles will not work. Wherever you glue the pieces together, they need to be flush, any step you have, will result in a gap. I get the best results by gluing the layers together one at a time and if you're clamping, you need to be very careful. Clamping also needs to be exact as it's very easy to have pressure more to one side than the other resulting in, you guessed it, a gap. These work best if you cut the squares so the grain runs with the short dimension, like you'd get if you were just slicing off a pen blank, this gets you away from end grain. End grain ones are horrible to turn, nothing but tear out. I had some success with negative rake cutters, but personally, I'll never make end grain ones again. Adding spacer material can be tricky but once figured out it's not hard to do. The spacer material does add to the tear out issue though. My personal taste is if using multiple woods, with varying color, spacer material is not needed. If you're doing all one color or wood, then spacer material is very much needed. Adding spacer material adds a lot of time to making the blank. These are not an economical blank to make, there's a lot of waste and you end up with a massive blank, pretty much dictated by the thickness of your boards or blanks. All in all, they are fun to make and if you stay away from end grain, they are not to bad to turn. Hopefully this will help some if anyone wants to give these a try. One more thing, if you're making these for a shorter barrel pen , you need to keep the little square thickness to around .150. The tutorials in the library are invaluable.