Textures/Power of two

The Power-of-2 Rule (POW)

Texture Image Sizing

If you've already tried modding clothing or props before, you might have been told to make sure your textures follow the 'Power of 2' rule. This is a game design concept that expands beyond just GTA, and it's something that is important for you to understand as you mod because otherwise you can run into issues in-game with how your textures display.

There are plenty of people who have explained this better than I could already, so instead I will recommend for you to read this article: https://www.katsbits.com/tutorials/textures/make-better-textures-correct-size-and-power-of-two.php

and I'll leave a quote from the article here:

In short it's a set of simple criteria ensuring 2D image assets conform to regulated sizes and dimensions, which typically manifest as; 1) width/height being divisible by "8", and/or 2) width/height that can be doubled-up or divided-down by "2". In other words any image that is "8", "16", "32", "64", "128", "256", "512", "1024", "2048" (or higher for more modern games) pixels in one or more width/height direction, is considered valid and properly optimised for quick loading into a game and processing into memory.

In other words, all of your textures should be "power of 2" in both width and height, although the image does NOT have to be a square. So you can have 1024x128 or 512x256 and so on.