How to make a link transparent

I'm working with on a page containing an SVG imported from Illustrator. I've been able to set a few sites on my list to use an <a xlink:href  . But I can't do it without my site having a black rectangle over it. Can you tell me what I'm doing wrong?

<a xlink:href="https://www.berkeleypottersstudio.com" target="_blank">
<title>www.berkeleypotters.com</title>
<rect x="18" y="2" width="450" height="50" />
</a>

Help, please!

Rick