There's a group buy on Sinkpad copper XM-L/ XP-G stars on BLF if anyone's interested. Basically they're copper stars that have a direct to copper (no dialectric) solder joint for the thermal pad under the LED, so heat transfer is significantly better than either standard alu or cu+dialectric boards. Cooler LED = more light
Cost is a reasonable $2.50 + $2-3 p+p in the US, plus you'll have to buy your own LEDs (like the $7.50 XM-L2 CW at Illumination Supply!). Not as cheap as alu stars (50c) but not a whole lot in the grand scheme of things.
Group buy thread:
GB: 20mm Sinkpad copper boards | BudgetLightForum.com
Original discussion thread:
32mm diameter copper boards: testing the water | BudgetLightForum.com
Mtbr's 2016 Winter Biking GearReviews and Roundups
Results 1 to 7 of 7