How BIG must my sign be?

How LARGE MUST my sign be? What size sign will best convey my message? From how far will people be able to read my sign?

These are questions we often get asked. As a joke, we tend to advise clients that, as a rule of thumb, (a) the bigger the better and (b) the sign should be as large as your budget allows. (Please note this IS a joke and while it is valid for outdoor signs, is not always best for intimate signs, where too big becomes gaudy.)

In truth, if a sign NEEDS to be visible from a specific distance – because it is located on the side of the road or it will only be viewed from moving vehicles or the sign is some distance from the point where it will be read (to name three of many scenario’s), then there are some rough scientific calculations that can be used to calculate the height the text needs to be in order for the text to be visible from a specific distance, as well as from a distance at speed. Please remember, at best, these calculations are rough guide, as they do not take into account ALL factors that affect visibility, especially height above the viewer.

The table below has been adapted from information taken from For more in depth calculations, especially for measuring legible distance while driving, please visit

It is important to remember that the table below refers to LETTER height ONLY. This means that if you have multiple lines of text or multiple words or either of these combined with a logo, the SIZE of THE SIGN will change, with the dependent factor being the DISTANCE at which the TEXT must be legible.

legible sign distance

For assistance for any signs, especially when you need to calculate sign size in order to make the sign legible, please call #SignForce on + 27 (0) 11 440 7524 / 5 or email

#Signs and the Coefficient of Change

Coefficient of Change

Experience is an amazing, if somewhat costly, teacher.

We at #SignForce we recently asked to maintain a #sign (#signmaintenance) where the lights had stopped working. When we touched some of the letters they literally fell apart.

Now let me give some background. #SignForce did not initially make the sign and we don’t know exactly how old it is. We do know it has been in it’s current position for 30 months when the sign moved with its owner. The reason I am explaining this is when one hears that the sign fell apart, it is common for the first thought to be that is is a result of poor workmanship, which I do not believe is the case in the instance.

Back to experience and the difference in the coefficient of change.

A while back – in 2010 – #SignForce manufactured and installed a 3D sign that was attached to the glass face of the building – the sign is in fact a total of eight stories high. One of the lessons that was learned from that installation is that, if the coefficient of change – the rate at which one material expands and contracts when it heats or cools in relation to a second material – is too large, one or both of the materials will literally tear themselves apart.

On inspection of the letters that fell apart, it seems this is the issue. The #stainless steel and #acrylic that were glued together simply placed too much strain on the #acrylic causing the acrylic to fracture in multiple places.

While the two materials CAN be attached to each other, various factors need to be taken onto account in order to prevent fracturing – something that comes with experience and expensive lessons.

If you are looking for a sign that combines various materials it may be worth approaching a business like #SignForce who have been around the block a few times and could thus be able to assist without the sign falling apart.

Contact #SignForce now on 011 440 7525 or at to get assistance and an obligation free quote.