Installing foam letters
Once you receive your foam sign letters order, take care in opening the box. If you use a box cutter or sharp instrument to open the box, be careful not to cut into your letters. Cut through the tape only. Do not cut into the box as you may inadvertently slice into your sign lettering.
As you remove your very light weight foam sign lettering from the box, you will notice that we have separated each letter using wax paper (for the economy foam) to keep the letters from coming into contact with one another. The lettering is recently painted, and they are dry, but they may stick together if you lay them on top of one another without something between each letter to keep them separated.
Depending on the size of letters ordered, the premium (custom typestyle and thickness) letters may be individually bagged.
How to layout and measure sign lettering
Lay 
out your letters along a straight line; you can use a sidewalk, the edge of a building where the sidewalk meets the building, a straight 2×4 board, a chalk line, or just about any straight line you can use. You’ll need a straight line to get an accurate measurement of your sign after all of the letters are spaced and laid out on the ground. If you're unable to find a straight line, you can use a long string or rope stretched out in a straight line.
After you have all of the foam sign letters laid out in a straight line on the ground or surface and each letter spaced the same distance apart, you then measure the sign’s total length. Once you know the total length of your sign, you can deduct the total sign lettering length from your wall length, and that will give you the exact amount of wall space left after installing your lettering.
Take a look at the example sign. The letters were laid out using a straight line on
the sidewalk. The total length of their sign letters, when laid out, was 12 ft wide. Their wall was 18 ft wide. So we know that they had 6ft of extra wall space left on the wall after they subtract the length of their pre-spaced sign letters from the total length of their wall (18ft wall, minus 12ft sign = 6ft., or 3 feet on each side).
In the example, the customer wanted their sign to be in the center of their storefront wall. They used a yardstick to make a straight line across the storefront. They knew that they only had 6ft of wall space, so they installed their first letter 3ft from the right end of the storefront, and after they installed their last letter, it ended up exactly 3ft from the other end.
Foam lettering adhesive
Installing foam sign letters can be simple; all you need is 100% silicone adhesive (exterior). No drills, nails, screws, or brackets are needed, so no damage to your storefront wall surface. You can purchase silicone adhesive from most hardware stores for around $5 per tube. We recommend clear silicone. See pics below on how to apply your silicone.
Apply a single line of silicone to the back for letters 12-inches or less or a double line of silicone to the back of letters larger than 12 inches tall.
Practice installation:
If you want to be sure that your storefront sign will be straight and centered on the wall before applying the permanent silicone, you can install your foam sign letters using any inexpensive double-sided tape first and use the silicone after you’re satisfied with the way the sign looks when installed with the double-sided tape.
After you’ve installed all of the foam lettering to your storefront using the double-sided tape, if the sign is centered and looks the way you want it to look, you can then remove one letter at a time from the wall, peel off the double-sided tape, apply the silicone and press it back into place on the wall, continue one letter at a time until you get to the end of the lettering on the wall.
Why double-sided tape?
The benefit of installing all of your sign lettering using the tape method, before applying the silicone, is just a precaution. Let’s say you began installing your lettering using silicone adhesive. After you have installed most of the sign letters, you realize that you made a mistake in your measurements, you would have a lot of silicone to clean off the wall before starting over, and silicone isn’t easy to remove.
By using the tape method, if you made a mistake in the measurements, it will not be a big problem. Remove the lettering and start over, with no silicone to clean off the wall. You have the option to adjust the lettering as many times as needed until you get it right using the tape method.
Most people do not use the tape method because as long as your measurements are correct, you won’t have any issues. As an example installation, you have a storefront 20 feet in length and an 18-foot wide sign. If you wanted to center the 18-foot sign on your 20-foot wall, you would install the sign one foot from the end, which leaves one foot on the other end.
Installing foam letters is similar. Measure twice or more times, install once.