Chapter 13 419 the gel. It has been the convention for many years that ingredients that impart an elastic texture to the gel, manifested in a stringy or choppy texture, should be avoided. However, during the past two decades products termed “novel textured stylers” that depart from the traditional clear, thick, and shear thinning gel characteristic of a typical carbomer-based gel have evolved. Now many different formats, examples of which are clays, putties, fiber texturizers, soufflés, taffies, waxes, sticks, whipped textured yogurts, chiffons, glues, serums, and sprayable milks, may be acceptable. This range in product forms leads to variation in rheological characteristics. These allow the creation of new styles for example, clays and putties can be added to short dry hair for a textured or layered effect that is difficult with a shear thinning carbomer gel. Besides the performance aspect, consumers like the novelty of different textures from an aesthetic point of view. Although spray gels deliver the fixative resin onto the hair in the form of a spray, they are not considered hair sprays but rather styling gels that are sprayable. To achieve this rheology the product must be very shear thinning and the fixative polymer not of a high molecular weight. Examples of gellants that can shear thin so that they can spray from a mechanical pump are carbomers and their hydrophobically modified derivatives, hydrophobically modified alkali-soluble emulsion polymers such as acrylates/beheneth-25 methacrylate copolymer, PVM/MA decadiene cross-polymer, and acrylic acid/VP cross-polymer. Here the shear thinning is so great that at rest the product behaves like a gel, but as a liquid it is mechanically stressed in the actuator. The spray is usually added to damp hair and then styled as usual as opposed to a hair spray which serves as a finishing product after the styling process is complete. Formulation variables: Each product format can be distilled into a framework that consists of a list of ingredients at specified levels that make up the essence of the formulation. As we have seen with the styling gel, there is basically the fixative resin and the gellant, and with an aerosol mousse, which will be described in a subsequent section, there is the propellant and the resin solution with a foaming