When using CATIA, the user may find that using an operation alone does not give the required result. It is using a combination of tools that gives the user the required result. This is often a matter of playing around, or actually understanding what needs to be done. In the video below, the upper surfaces of the Car Fender do not blend nicely with the lower surface. Using tools such as curve smooth, coupling curve within the Blend definition and Quick select, the user can quickly rectify the issue.