Usually you tell the printers to print in a specific Pantone colour or using CMYK. The Pantone shade tells them what ink mix to use but it's not what the final printed product will look like as that depends on what you're printing on. Say you've a coffee shop and have your logo printed on a white paper cup and also on a brown Kraft box the same Pantone ink will look very different.

Tring to work back from "I want all my printed items to look like Pantone #12345" to selecting the required inks for different materials is a very hard job.

Another problem is Pantone release a new book each year. You'd like to think that is just to ensure the reference colour charts don't fade etc, but they sometimes change the actual colour mix.

In 2023 Pantone changed how they mixed colours [1] which means some visual differences. We had a customer using 544u and that changed quite dramatically with the new mix, all of their branding looked quite different. We had a long fight with the printers trying to resolve this.

[1] https://www.printweek.com/news/article/pantone-explains-cont... > all Pantone Colors were now mixed from 11 base inks plus a colourless extender, a simplification on the previous 18 base inks.