Purchase a cover for your baseball display. The size of the cover will determine the size of your baseboard. A plastic cover weighs less and is more likely to withstand abuse than a glass cover, but glass covers look classier than plastic ones. Glass and plastic covers can be found at most hobby and craft stores.
Find a piece of wood that will be the base of your display case. The best place to get the wood is your local lumberyard. Purchase a simple 2 by 4. Have the lumber yard cut it to size for you.
Decide what you want to do with your base board. Plain lumber that hasn’t been treated looks tacky. Most people choose to stain their base, but if staining seems a little too traditional for your tastes, you can always paint it in your team's colors.
Glue a piece of felt to one side of your base--the side that will be inside your baseball display case.
Stain or paint the balsam sticks to match your base.
Glue the balsam sticks in the middle of your base in such a way that they make a square. This will provide a stable base for your prized baseball.
Place the baseball on the balsam stand.
Settle the cover in place.
Place the baseball display case in an important spot where it can be seen and admired by everyone who visits your home.