"Times" sentences average 15 words, according to analysis. With average sentences of 8 words or less, readers understand 100% of the story. So what’s the right length for text that makes Pins stand out?
Looking forward to hearing your experiences.
Do you mean text length for Pin descriptions?
The Pin description is where you provide more context for your image. This is what makes your Pin even more rich and understandable for your customers. Do some SEO research before you publish your Pins, try to add relevant keywords not only popular keywords. Use strong keywords and you don’t have to use all 500 characters to say it all!
The best Sophia
Less is more but it also needs to be the right text. "Speak to the Pinner" use just the right copy to make them stop their scroll. Keep in mind larger text stands out more (especially on mobile where Pins are smaller). You can also test call to actions. Here's a post with several examples (hope it helps!). http://www.toritait.com/compelling-pinterest-creatives/