Master Pages & Themes
.master May have several in a site Add New Item / Master Page .master file is template .asp is content MasterPageFile="~/myMaster.master"
Where <asp:contentplaceholder id="ContentPlaceholder3" runat="server"> If you have content, it will be default content. Be careful with relative URL's, which are relative to the master.
URL Alternatives Relative Absolute Programatically Generated
Themes Theme = "simple2" In directive
Skins Make a folder App_Themes Any folder in it contains a theme, by the name of the folder Name your folder uniquely .skin Can only affect appearance SkinID="myTextBox"
Skin is a default control, with appropriate style. EnableTheming = "false" You can do much of this in web.config CSS is automatically applied if in the folder, even if more than one Can apply Themes and Skins dynamically, in PreInit event.