BoundColumn.aspx font size:
C# Source: BoundColumn.aspx   fetchData_oledb.cs   
View Sample
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.OleDb" %>

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

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

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

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

<hr size=1 width=92%>

<p align="center">

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

      <columns>
         <asp:boundcolumn headertext="Type"
            datafield="ProductType" />
         <asp:boundcolumn headertext="Brand/Model"
            datafield="ProductName" />
         <asp:boundcolumn headertext="Description"
            datafield="ProductDescription" />
         <asp:boundcolumn headertext="Price"
            datafield="UnitPrice"
            dataformatstring="{0:c}"
            itemstyle-horizontalalign="right" />
      </columns>

   </asp:datagrid>

</p>

<hr size=1 width=92%>
<!-- #include virtual="~/shared/viewsrc.inc" -->

</body>
</html>