With few exceptions, toilet soap in bar form is produced by a milling or refining, extrusion, and stamping operation as a firm quick lathering bar.  The soap base is most commonly composed of the sodium or sometimes mixed sodium/potassium salts of tallow and coconut oil fatty acids.  An exception to the milling operation is provided by floating soap, which is made by a whipping or beating process that disperses air through the soap. The bar so produced is lighter than water.  Framed soap is made by pouring hot, molten soap into a frame with the resultant large soap block later being cut into bar-sized pieces, which are stamped into appropriate shapes.  Toilet bars are usually made with fragrance and colorant or whitener.  Use of a preservative is common. By use of optional ingredients special effects may be obtained.  Some special types of soap are: deodorant, medicated, superfatted and transparent.