Skins
RadGantt uses skins to control its overall look-and-feel. A skin is a set of images and a CSS stylesheet that can be applied to the control elements (items, images, etc.) and defines their look and feel. By default all controls in UI for ASP.NET AJAX suite have a polished look and feel which is consistent across the whole product line.
Built-in skins
These are the skins provided by Telerik. They are embedded in the Telerik.Web.UI.Skins.dll assembly(except the Default one). To use a built-in skin the user only needs to set the Skin property of the control.
Below is a set of the Telerik RadGantt skins:
The Material skin is available for the Lightweight RenderMode only. If you experience visual issues with it, make sure your controls are not using the default Classic mode.