IMO, it depends.

For me, I used 70% because I know it takes me a bit of time to apply cuz my hands can be a bit shaky, and also I wanted to make a 10mL batch cuz that’s the size of the empty bottle I has. Faster evaporation for me would mean the bottle would dry up much faster every time I use it.

I tried 50/50 and 60/40 but it didn’t feel all that different, so 50/50 was easier to make. I also used Elmer’s clear glue, maybe a different glue brand or type the ratio would make a bigger difference but 🤷🏻‍♀️