A.       Needle gauge.  There are different sized needles for different projects.  The 32 gauge is for needling hair onto vinyl dolls and for needling coarse fiber such as Karakul.  (I call this the coarse needle.) The 36 gauge needles are used for needling medium fleece such as Romney or Cotswold.    (I call this a medium needle.)  There are also 40 and even finer gauge needles.  The higher the number with wire (as with thread), the finer the diameter.  So 40 is smaller than 36.  I use the 40 for needling very fine fibers and for needling fine pre-felts onto silk cloth backgrounds. (I call this needle the extra-fine needle.) I use the 38 for merino fibers and call it a fine needle.  I like this needle for needling merino pre-felts onto a cotton cloth ground. The coarser needles are good for preliminary work, doing the deep penetration necessary to “rough” in a sculpture for instance.  The finer needles are better for detail work done when the felt is already partially hardened by the coarser blades.  You do not need to penetrate deeply into the felt surface to add details and the finer gauge leaves less of a hole.