One of the most challenging tasks for injectors is deciding which product to use and how much. When we assess the face, we should be using a global approach to optimize our aesthetic outcomes. Considering the frame of the face first is essential. It is like painting. You cannot paint a beautiful work of art unless the canvas is stretched on a frame. I start by assessing from the top and lateral and work my way down the face. As I evaluate, I also am deciding which product to use and how much. Knowing the rheologic properties of your products is critical. These are not one size fits all. Think about the platform, plane, purpose, and placement technique. Are you projecting the lateral malar apex or smoothing peri-oral rhytids? G' (G-prime) is often referred to as the lift capacity of the product. I look at this as the product's ability to project overlying tissue. High G' products most often are injected deep or supraperiosteal. A low G' product is suitable for intradermal or subcutaneous injection. I also think about G" (G-Double Prime) or the cohesivity of the product. Does the product maintain its shape, or is it more spreadable? X-strain refers to the flexibility of a product. High X-Strain products are soft and stretchable, where a low X-strain product will be stiffer. In areas of increased mobility, such as lips, a high X-strain product would be preferred. Hydrophilicity is the affinity the product has for absorbing water. Some products are more hydrophilic than others. In an older patient, high water absorption can create heaviness and an aged appearance. Choosing the correct product for the area being corrected is crucial.