A by-product of a prick and stitch design is the holes that the thread passes through. Some people regard them as an important part of the design that should show and others think that they are better minimised.
When you consider that there is a branch of card making that just uses holes pricked in the card to produce the design it is easy to see where the first school of thought is coming from.
However, if you belong to the group that think they should be minimised you will be looking for a way of doing it. I have found that gently rubbing the back of the design with the back of a teaspoon will help make the pricked holes less visible. This will push down the raised edges created when the needle passes from the front of the card to the back. If you put the card on a firm surface while you rub the teaspoon across the back it will also help flatten some of the edges on the front.
The above illustration is from the Stitching Cards web site and used with kind permission.