Here are two types of neck blanks. One is a solid piece of cherry, and the other is five pieces of ash that I glued together. In my experience, both are satisfactory for necks. Yellow (aliphatic) glue yields a bond as strong as the wood itself between carefully joined pieces. It is often easier to find 4/4 wood species (like the ash, above) at local lumber yards and home improvement centers. 16/4 examples (like the cherry pictured here) are often only available through specialty lumber yards or through online auctions.