border-width:1px
border-width:4px
<table width="230" style="border-color:#990000; border-width:1px; border-style:solid;">
<tr>
<td></td>
</tr>
</table>
border-width:4px
tborder-width:8px
<table width="230" style="border-color:#990000; border-width:4px; border-style:double;">
<tr>
<td>border-width:4px<br>
border-style:double</td>
</tr>
</table>
border-width:1px
border-width:4px
<table width="230" style="border-color:#990000; border-width:1px; border-style:dotted;">
<tr>
<td>border-width:1px<br>
border-style:dotted</td>
</tr>
</table>
border-width:1px
border-width:4px
<table width="230" style="border-color:#990000; border-width:1px; border-style:dashed;">
<tr>
<td>border-width:1px<br>
border-style:dashed</td>
</tr>
</table>
テーブルを二重で設定
テーブルの背景色を設定
<table width="230" style="border-color:#990000; border-width:1px; border-style:solid;">
<tr>
<td> <table width="100%" style="border-color:#990000; border-width:1px; border-style:dashed;" cellpadding="0">
<tr>
<td></td>
</tr>
</table>

テーブル罫線の種類