You can apply custom CSS to give your Novator theme product images a border. Here is a small sample of code that you can try:
```css
.product-photo {
border: 2px solid #000; /* Change #000 to your desired border color */
padding: 10px; /* Optional: adds space between the border and the image */
}
```
Just be sure that your product photos use this class. To suit your taste, you can change the border's color and width. Please ask for more help if you need it!