Typography is a core part of a brand, as so much of what a brand creates involves text, how that text is set and appears visually makes a huge difference to how a brand is able to portray its message and plays a huge part in it success or failure.
As part of my logo creation process, I made a decision to use the serif and sans-serif versions of a single typeface family to create the same different wordmark. The typeface family I selected was Alegreya. I did consider using Alegreya as my overall brand typeface but I discovered issues surrounding its readability which meant it would not be suitable for UI copy or any long form text content I need to create. The sans-serif version will work well for items such as advertising (posters, billboards etc.) and my H1 headers where the content is short and the larger font size will overcome any readability issues I have discovered.
From some online research I knew that the key letters and numbers that need to be clearly differentiated were the I, J and 1. So to look at how readable each option was I typed each of these characters in a document beside each other. I found that for Alegreya the differences were not as clear as I would like, and this made my decision that Alegreya would not be my UI typeface.
For a UI font I looked towards the more common fonts used by apps and websites, and decided to look at IBM Plex Sans, and when I compared it to Alegreya it was much easier to identify the similar letter forms.
For my UI typeface I decided on IBM Plex Sans, based on my readability testing I knew it was a much better option than Alegreya. However, I knew that other typefaces such as Inter would also be good options. The main reason I chose IBM Plex Sans was that compared to other typefaces with good readability, it had a little more character to my eye, especially as it has ligatures, something Alegreya also has, making a link between the two typefaces. I believe this will make the combination of the two more cohesive and that they will work harmoniously together.
From my logo creation, I already had the Alegreya typeface from the logo. What I needed to do was to test whether it could work as a overall brand typeface. I found that it had readability issues and this helped me to make the decision not to use it within my UI. This drove me to select IBM Plex Sans as my UI font.