The Cascading Style Sheets (CSS) Working Group and the SVG Working Group invite implementation of the Candidate Recommendation of Compositing and Blending Level 1. Compositing describes how shapes of different elements are combined into a single image. There are various possible approaches for compositing. Previous versions of SVG and CSS used Simple Alpha Compositing. In this model, each element is rendered into its own buffer and is then merged with its backdrop using the Porter Duff source-over operator. This specification will define a new compositing model that expands upon the Simple Alpha Compositing model by offering: additional Porter Duff compositing operators; advanced blending modes which allow control of how colors mix in the areas where shapes overlap; compositing groups. In addition, this specification will define CSS properties for blending and group isolation and the properties of the ‘globalcompositeoperation’ attribute as defined in HTML Canvas 2D Context, Level 2.