DataGridTemplateColumn.aspx font size:
C# Source: DataGridTemplateColumn.aspx   fetchData_sql.cs   
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>

<html>
<head>
<title>DataGrid TemplateColumn Example</title>
<link rel="stylesheet" href="/shared/netdemos.css">

<script language="C#" runat="server" src="fetchData_sql.cs" />

<script language="C#" runat="server">
   void Page_Load ( Object src, EventArgs e ) {
      if ( !IsPostBack ) {
         string query = "SELECT * FROM Titles";
         myGrid.DataSource = fetchData ( query );
         myGrid.DataBind ( );
      }
   }
</script>
</head>

<body>
<!-- #include virtual="~/shared/top.inc" -->
<div class="header"><h2>DataGrid TemplateColumn Example</h2></div>

<hr size=1 width=92%>

<p align="center">

   <asp:datagrid id="myGrid" runat="server"
      width="92%" cellpadding=5 font-size="9pt"
      gridlines="horizontal"
      headerstyle-backcolor="slategray"
      headerstyle-forecolor="ivory"
      headerstyle-font-bold
      itemstyle-verticalalign="top"
      autogeneratecolumns=false>

      <columns>
         <asp:templatecolumn>
            <itemtemplate>
               <img width=60 align="top" 
                  src='<%# Eval ( "title_id",                      "/shared/images/title-{0}.gif" ) %>' >
            </itemtemplate>
         </asp:templatecolumn>

         <asp:boundcolumn headertext="Title"
            datafield="title" />
         <asp:boundcolumn headertext="Notes"
            datafield="notes" />
         <asp:boundcolumn headertext="Publication"
            datafield="pubdate"
            dataformatstring="{0:d}" />
         <asp:boundcolumn headertext="Price"
            datafield="price"
            dataformatstring="{0:c}"
            itemstyle-horizontalalign="right" />
      </columns>

   </asp:datagrid>

</p>

<!-- #include virtual="~/shared/viewsrc.inc" -->

</body>
</html>