Padding affects backgrond color of link - hyperlink

Question

I have padding on images and the padding affects the image link because there is a black line
Style
a:link{background-color:black}
img{padding:20px}
Html
<img src="blank">
So in Simple terms there is a black line coming from the image and I want to get rid of it. I can't get rid of the styled link because I use it for other links

Answer 1

Instead of black, use transparent or none
SNIPPET
.tran {
background-color: transparent;
}
.none {
background-color: none;
}
img {
padding: 20px
}
<a href="#/" class='tran'>
<img src="http://i.imgur.com/o1RbMvI.png">
</a>
<a href="#/" class='none'>
<img src="http://i.imgur.com/o1RbMvI.png">
</a>

Answer 2

If you want specific style for one link, but you don't want it to affect the others or be affected by the others, I would set up a specific class for the links you want to have a background-color: black; and then a separate class for the link that you don't want affected by it. zer00ne provides a sufficient answer for this. Just add class="tran" or whatever you want to name them into your links that you want to be connected together with whatever style you use in .tran{}, as shown in his answer. Play around with grouping things into classes and using the classes to style more specific elements in your CSS. Best of luck!
in css file:
.black{background-color:black;}
img{padding:20px;}
HTML:
<p>
<img src="blank">
<img src="blank">
</p>