Sign Letters F A Q

Some helpful information we're often asked about. If you still have questions try us at (877) 294-8717.

Frequently Asked Questions

  1. Q: What kind of letters do I have (or need*)?

    A: The two most common types are Flexible and Rigid. Flex letters need to be slightly bent to be inserted into the Flex Letter Sign Track (Flex Track picture). They are thin (the approximate thickness of a credit card, .030″ or slightly thinner), so they bend or “flex” easily. Flex track has the same depth slit in the top and bottom of the track.
    IMPORTANT - Flex letters should not be used on an enclosed sign.
    If your letters are thicker than a credit card, they are Rigid Letters.
    Credit Card = .030″ (.76mm) thick.
    Flex letters = .030″ or thinner.
    Rigid letters = .060″ (1.52mm) or thicker.
    What does DR stand for?

    Rigid letters are thicker, usually the thickness of two or three credit cards (.060″ or .090″), and do not need to be bent or bowed to be inserted into the Rigid Letter Sign Track. Rigid letter track is often a 3 component track consisting of a Top, Mutual (or Dual), and Bottom. The top of the letter goes into a deeper slot, allowing the letter to be pushed up, then in towards the sign, and dropped down into the track below. (Rigid track illustration). Part of the top of the panel will still be into the top slot so the letter does not fall out of the track. Remove the letter by reversing the procedure. Note: On some signs, Mutual track is used for the top track and bottom track.

    When measuring for size, measure the height of the letter, the height of the plastic the letter is printed on, and the thickness of the plastic. Let's take the height first, and we'll deal with the thickness next. For example, 8″ on 8 7/8″ clear back (panel) means that the letter itself is 8 inches high and the clear plastic (the actual piece that fits into the sign) is 8 7/8 inches high. The 2nd measurement is the most important since that's what actually fits into the sign track.

    * Note - If you acquired a sign with no letters, look at the pictures (Flex Track picture) and (Rigid Track picture). Compare the track on your sign to the pictures. Flex track is approximately 1 inch high, rigid letter track (the middle or dual track) is 1 1/2 to 1 3/4 inches. Next, cut a rectangle out of cardboard (like a cereal box) and cut it to fit into the sign. Measure the cardboard and this should be the height of the plastic you need to order. If you are not sure, call us - (877) 294-8717 or e-mail -

  2. Q: How do I determine the thickness of my letters?

    A: The easiest way to determine if you have a flex or rigid letter is to compare it to the thickness of a credit card. If it's the same or slightly less, it's a Flex letter. Anything thicker is a Rigid letter, and Rigid letters don't fit into Flex letter track. It's actually the type of track on your sign, the strips that hold the letters, that determines what type of letter you have or will need. Flex letters don't work with rigid letter track, and rigid letters don't work with flex letter track. Rigid letters typically start out at the two credit card thickness (sometimes called an “econo” letter) and go up from there.

  3. Q: Other than the obvious, what's the difference between an Econo rigid letter (approximately .060" thick) and the others (.080" and .090")?

    A: The obvious being the “others” are thicker and usually, as you might expect, a little higher in price. The one thing an econo letter might do that the others won't is to occasionally, under certain wind conditions, move or “walk” sideways in front of another letter. They don't come out of the sign, and it's not a common occurrence, but just be aware that this can happen.

  4. Q: Why are Rigid Letters so much more expensive?

    A: The acrylic that most rigid letters are printed on is a higher quality, with additives that protect them from weathering, turning yellow and getting brittle. These are often designated DR (Rohm & Haas). Another obvious reason is because the rigid letter plastic is thicker, but it's the type and treatment of the acrylic that accounts for most of the added expense. The cost is more, but the result is a letter that lasts 10 times longer. Rigid letters are more often used in overhead signs, out of reach. This, combined with the different track configuration, means they probably won't need replacing very often, which justifies making them more durable. Flex letters should normally last around 3 to 5 years, and sometimes longer depending on care and how often they're changed. Because they are used in ground level signs, the lower price makes them more attractive when replacement is needed due to factors other than age. Standard flex letters should never be used on an enclosed sign (a sign with doors on it).

  5. Q: Is different Track used for Flexible and Rigid?

    A: The track that holds flex letters allows you to put the letter in the bottom track, then flex it to get it into the top track, or vice versa. The track for rigid letters is a little different, you must put the letter into the top track, push it up then drop it down into the bottom track. A flexible letter may bulge out in the center, between the upper and lower track, a rigid letter should stand straight up and can slide in the track. Examples of each can be seen at the bottom of our Sample Letters page. Pictures of flex track and rigid track. Rigid letters are used in overhead signs (as well as some ground level signs) and can be changed with a “change pole”, flex letters must be inserted by hand. Rigid letters are usually done on a better grade of acrylic and last much longer then flex letters.

  6. Q: Since Rigid Letters are more expensive, can I use Flexible instead?

    A: Size can be a problem here, back height between Flex and Rigid is not always the same. If the same size is available, a flexible letter will fit into a rigid track (a rigid letter is too thick to go into a flexible track). A Flex letter is “gripped” top and bottom when inserted into the proper track, but is often very loose when used in a track meant for Rigid letters. Because they are thin, a flex letter can fall down behind the rigid track and not stay in place. And when not used with the proper track, they tend to blow out in the wind, or to be blown together and bunched up. Another factor to consider is that flex letters WILL NOT work with a change pole. For these reasons it is not recommended.

  7. Q: My track is brittle and breaking, is new track available?

    A: Track is usually “pop” riveted onto the sign face, and is replaceable. We carry both Flex letter track and Rigid letter track. In addition, the sign face itself can also be replaced. Sign faces can be purchased with or without track already installed on it, in several different sizes. Sign faces with Flex track installed can be rolled and shipped UPS (oversize). If Rigid track is installed, the face must be crated and shipped via a Freight company.

  8. Q: What does "DR" stand for (.060DR)?

    A: Rigid letters designated DR - DR Acrylic (.060DR) - It is an all-acrylic resin that combines the toughness associated with other impact plastics and the outstanding transparency and UV resistance of conventional acrylic materials. Higher cost and good heat resistance. Much slower yellowing than PC (Polycarbonate) and higher breakage resistance than AC - AC Acrylic.

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