Thanks, I assume you are talking about adding the border to the source file, and then re-uploading. Of course that is probably the simplest solution, and possibly the only one.
My issue is that I took over this store. We have roughly 50 clients using it, each with their own static letterheads and envelopes. One of them has roughly 25 locations, each with their own static letterheads and envelopes.
I was hoping there was an option like what we are using for the catalog preview image. Code below.
<style type="text/css">
.TnProd input[type=image]{
border: 1px solid black !important;
}
</style>
Otherwise we will need to go back to the source files, change and re-upload possibly hundreds of images.