You need to think outside the box if you like greeting star map designer abilities to get noticed and purchased by consumers. Most greeting card companies have in house greeting star map designers that pump out designs for them all day long. They do not really have to see your designs. Do not ever take it personally. It is easier for a company to employ a greeting star map designer and pay them a salary than to take chances on freelancers. A business that prefers to hire may also maintain your designs as their own as soon as you become their worker. You design the way they want you to. Basically, you do the grunt work, they take the credit.
Another reason could be lawful. A freelance graphic artist could assert their designs were stolen from the business and that spells trouble for the department. That can also lead to a company to never look in the greeting star map designs. It suggests trying proper stations. Get a broker to represent you and have the agent submit your designs. Having the aid of an agent will provide you credibility as an artist and will help take care of potential legal issues. Get a list of businesses you want your designs to visit and have your broker submit away. An alternative would be to have a job with a business you are targeting in the event you do not mind not having control over your designs. Getting hired means not being able to work at home and losing control of your designs.
Doing freelance work is better in the long run as you will have more freedom to design on your own creative environment with no constraints. I remember attempting to solicit some designs to a greeting card business years back. I thought it would be simple to do. I enjoy biblical stories and believed it would be simple to star maps design cards. All I would have to do is draw, paint and submit my art work. I was green at the time and did not have any idea of how the greeting star map design business functioned. In actuality, I was so green I sent my first drawings in believing the company would send them back. I never watched those drawings of course. It was a long time ago and I do not recall the business name. Always submit copies of your art work rather than your originals.