Prevent wrapping <span> tags for ASP.NET server control

I am writing various ASP.NET Server controls and am needing to remove the tags that wrap my control by default. I am aware that you can change the tag to a different tag (as in this question, How Do I Change the render behavior of my custom control from being a span) but how can you prevent it?

I am inheriting from WebControl (can also inherit from CompositeControl).

I typically get:

<span>Control output</span>

I need:

Control output

I am overriding RenderContents(HtmlTextWriter output) and the CreateChildControls() methods (across various controls). My immediate need is to address the issue using the RenderContents(HtmlTextWriter output) method.