To carefully pour a small amount of liquid that balances as the top layer of a drink. This is done by using the back of a barspoon to gently disperse (or float) the ingredient on top of the ingredients already in the glass. This technique is often used to to make layered shots
and works best when applying the theories of the specific gravity
of different liquor, ie. heavier liquor sinks and lighter liquid rises. To keep the layering effect the drink should not be stirred and practice is the best way to get the feel for creating clean layers.