Here's a quick tutorial on how to use reNix, my Nixie tube layer font from my Analog Digits packs! I'm using Affinity Publisher, but these steps should be mostly do-able in other layout apps and word processors.

Step 0: The inspiration

There's a lotta photos and videos of Nixie tubes out there in different electrical configurations, and with different image qualities and properties, all of which changes how they look. Still, we can make something that fits roughly into this kinda range of how Nixie tubes can look. I based the font on a few photos, including these two (you can find the top photo, and a lot more, at this electronics hobbyist site):

Step 1: Set up the layers

Make a text-art layer, set the font to reNix, type in your text, and duplicate the layer twice. Open the Typography pop-up (Ctrl/Cmd+Shift+T). Select the top layer and apply stylistic set 2 (ss02/“unlit in front”). Select the bottom layer and apply stylistic set 3 (ss03/“unlit behind”). That leaves the middle layer as the default “lit” filaments. At the end, it should look like this:

Most word processors and layout apps will have some way to access these font features like stylistic sets (if the font has them). You can find more info in your app's documentation or in the user guide for reNix!

Step 2: Flat colours

Give each layer a fitting colour. I've gone with a pale orange for the lit layer, black for the unlit filaments in front, and a very dark red for the unlit filaments behind (since the light from the lit one will reflect off them a bit).

Step 3: Glow

Apply a bright orange glow to the lit layer. Now it's looking a little more realistic!

The Affinity Suite lets you apply separate inner and outer glows. I've used the same colour and edge-aligned the inner glow (instead of centre-aligned) so they blend into each other.

Final step: Shadow

Apply a deep red shadow to the lit layer, with a 0-degree offset (so the shadow appears directly under the glyph, like a glow effect).

This isn't really a shadow, just a way to get a more complicated glow that starts orange and fades to red. This shadow also helps to highlight the unlit filament stack behind.

Extra options

This is just one way of using reNix, though—for instance, you could apply stylistic set 1 (ss01/“unlit”) to the lit layer to swap the bulky “lit” glyphs with thinner ones, then cut the inner glow, for a sharper and more crowded look:

You could even use the unlit singles (ss01) to make properly 3-dimensional graphics where each filament is drawn separately! But that's beyond this tutorial.

Hope this helps! If this tutorial caught your eye, you can find reNix in my Analog Digits font packs, along with other fonts for retro electronic displays.