Auk it was an idea, sorry if it wasn't up to your standards!!
Oh, but I hardly have standards! Putting a tree on a on a humidity tray - outside, in drying winds - just goes against my logic. Any vapor coming from that tray will be blown away and will do exactly nothing for a tree.
BTW:
A drip tray is a small tray that goes with a bonsai pot, to protect your furniture from water coming out of the drainage hole.
A humidity tray is a much larger tray, usually plastic. I've seen a test from someone on youtube, who tested such trays, but it made little difference, hardly enough to have a real effect on bonsai trees *1).
I have to humidity meters myself, they've been lying around here for quite some time now, as I wanted to repeat that test... haven't done it though. I may try one day.
It was just an idea I shared as people do on forums
Absolutely! And then you get a response. As people do on forums
*1) Movie is here:
Conclusion is that to have some effect, you would need a LOT of humidity trays - but the effect is minimal and hardly worth the hassle.