trying to make a glowing tube thats less than 25mm in diameter. I found a source of the silicone tube but it’s for 10mm boards. The only strips I can find that are 10mm are 30 LED/m and I want denser than that.
Do you need it to be flexible? If not you could consider something like: https://shop.pyrasied.nl/en/product/transparent-polycarbonate-tubes/
These folks have a great assortment of … stuff!
Where are you looking? What country do you need then shipped to? Any reason for APA102 specifically?
Most 60/m and less strips that I see are 10mm (eg from BTF Lighting). Though I’m mostly working with ws28xx. Especially now that they have backup data lines.