Seven Piece Multi Wood Necks Combined with exotics, these can be striking examples of multi wood necks. Shown are two Mahogany necks with 1/4" Cocobolo center stripes flanked with 1/16" Maple followed by 3/16" ebony borders.
Magnificent Maples:    Here are several examples of primary multi woods in Tiger Maple:  Top left: 1/4" ebony center stripe; 3 piece neck. Bottom Left:  two piece maple. Right:  Five piece 1/4" Bloodwood center flanked with DD Black Brazilian Tulipwood.

Five Piece Multi Wood Necks. Top to bottom, here are four classical slot head necks: Spanish Cedar with 1/4" Bloodwood center stripe flanked with DD Brazilian Tulipwood. Tasmanian Blackwood with 1/4" Ebony center  flanked with 1/16" maple. Tasmanian Blackwood with 1/4" Bloodwood center flanked with DD Brazilian Tulipwood. Tasmanian Blackwood with 1/4" Ebony center flanked with 1/42" padouk.
Top to bottom:   Single Piece Mahogany with Smile volutes and Gibson type heels: Five Piece Mahogany; Black Walnut  center flanked with 1/16" maple. Five Piece Mahogany; Cocobolo center flanked with DD Black Brazilian Tulipwood. Five Piece Mahogany; Tiger Maple Center flanked with DD Black. 12 String Neck;  Cocobolo center flankwed with DD Black Brazilian Tulipwood.

Scarfed Heel Necks Come in various wood combinations, the heel usually melded with a center stripe for strength. Seen here are Rosewood and ebony scarfed heels. The rosewood version has a matching wine glass backside veneer treatment and twin tiger maple flanking pins with mahogany as primary wood.
Tiger Maple Neck with ebony scarfed heel and center stripes.

Smile Volutes with Back side veneering Smile volutes can remain un-veneered, but  can be enhanced with the treatment shown.   These necks are mahogany with Mango and Cocobolo centers flanked with tiger maple. The veneers match the center stripes in each case.
More Smiles with Backside veneers on Cut Away necks    Top to Bottom: 7 Piece Mahogany neck with 1.8" rosewood center stripe flanked with 1/8" tiger maple and 1/42" ebony; rosewood backside veneer. Same, but  1/8" ebony center stripe and Macassar ebony veneer. Third is same as top neck. Fourth neck also has ebony center and with African Blackwood veneer.

Slot Head Necks with Wine Glass back side veneers. These necks have also had their regular top veneers placed.
Colleted Diamond Volute Examples   Mahogany with Bloodwood center stripe flanked with ebony.

Classical  Slot Head Neck  in the Baroque Manner. Rosewood lines are tilted 8 degrees in this style convergent towards the heel cap and head plate crown.  This makes a striking neck with the stability of a Honduras mahogany core and full length sound transmission quality of rosewood.

Another example, this time with fancy koa center stripe flanked with maple pin and of course, fancy koa veneer.
Arch Top Necks   Arch top guitars require different treatments for their necks.  The main feature difference is that a finger board extension remains visible above the sound board.

Occasional Odd Ones: The neck with no barrel is for a 1923 Wiessenborn Lap Steel Guitar.   The other end of the spectrum is this electric guitar neck; full body extension.
More Mixed Designs:   Very extreme tiger maple necks and various mahogany primary necks shown here.

The Extra Long and the Extra Short are No Problem:   These baritone necks, of single piece mahogany, sit in contrast to regular six string steel necks.
Ukulele Necks   These flea sized necks carry many of the same features as their larger cousins.

Alternate Primary Neck Woods:  Walnut   Walnut is also a tone wood and is generally unrecognized as such.  It also makes for some striking necks.
Another Alternate Neck Wood is Hawaiian Koa.   Neck to far right is Koa.   Other neck primary woods not shown have included Pernambuco, Cherry and Tasmanian Blackwood.