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Best Practices for External School Room Identification

Posted by Allstate Sign & Plaque on Oct 7th 2018

It goes without saying that schools today are taking security more seriously than ever before. Many new security measures are being put into place that address both prevention and response. One such measure is the proper identification of all rooms in the school building. This enables first responders to quickly get an understanding of where a threat may be located when they arrive on the scene.

As a sign and safety company that has helped a lot of schools with their room identification system, we’ve learned a few things about what works and what does not. In this post, we are going to go over a few key points that will help make your room identification system highly effective and help you avoid common mistakes.


The placement of your room identification stickers is probably the most important factor that will determine how readable they are. Using an adhesive faced sticker that is applied on the inside of the glass can be problematic due to window glare or tinted glass.

To illustrate this, we tested adhesive faced stickers placed on the inside of the glass vs adhesive backed stickers placed on the outside. We then photographed the results from the same distance and angle.

The results are quite clear. The sticker placed inside the glass is barely visible while the sticker placed outside is easily readable from a long distance.

Letter Height

The height of the letters directly corresponds with how far you can read the room ID from. We recommend a 4" letter height which should make it readable from up to 100 feet away. This is illustrated by the letter visibility chart developed by the Pennsylvania Transportation Institute, Penn State University and the United States Sign Council.


In addition to the height of the numbers, it is also critical to have a high contrast color scheme for maximum readability. We recommend either black or red letters on a solid white background. Without the white background, the letters tend to disappear into the glass from a distance. You can see an example of this in the comparison photo above.


For font selection, we recommend a simple san-serif font such as Helvetica or Ariel as they are clean and easy to read. More decorative fonts such as Times Roman or any other serif based font will be more difficult to read as you get further away.

Questions & Ordering

If you have any questions, feel free to contact us or call us at 631-242-2828.

To place an order for room identification numbers, visit the product page.