Thermark and Cermark are both Ferro companies so... As to Cermark (never used Thermark as I assume they're the same) with the exception of a trial of LMM14 (which is Cermark, and it melts foam brushes, FAIL) all I've ever used is LMM6000. I get mine from cermarksales.com -- right now I notice they don't have a 1000gm bottle (?) but the 500gm bottle is only $234. I notice Cermark's (ahem: IMO)
TOTALLY USELESS ULTRA is only $287 for a 1000gm bottle. I paid $400-something for a 1000gm bottle, and really wishing I'd just bought a trial size. It works fine except where it doesn't. Not once did I get an all-black result, ALWAYS blank or blotchy spots somewhere in the etch. And if you go over it again - a no-brainer with 6000- it only gets worse. I went thru the gamut of speed and power settings. The 'you can engrave faster with lower power lasers' tagline, well... To get best results I COULD get meant using 6000 settings.
Just a small bit of MY experience with Ultra. Note these letters are about 2" high, and these were the worst...
This is the initial run. 'Blotchy' is an understatement...
01.jpg
--this is what happened when I re-applied some Ultra and went over it again...
as I said above, it only got worse...
02.jpg
Next--
EL1.jpg
From the same re-apply as above--
and this is someone else's item that I'm screwing up!
EL2.jpg
And oh yeah- putting 6000 over it and hoping for the best doesn't work either.
How to fix? Had to sand down the whole thing...
SANDED.jpg
After which I applied some trusty ol' 6000, ran it
with my 15 year old 30w Explorer, and Voila--
EL9B.jpg
--absolutely perfect in comparison...
I've been going to try it on aluminum and brass and maybe glass just to see what happens, but as it is all that 1000gm bottle of Ultra is good for is a paperweight...
If everyone else is having the same success as you and I, the price may keep going down until they'll have to pay us to get rid of it. And if anyone is having GOOD luck with it, I'd sure love to know how...!
>>edit<< - just went back to the cermark website, and the 500gm bottle of 6000 I quoted is actually LMM14--oops... as of now they only have 50gm bottles... THAT's not going to work for me I'm afraid...
>>edit II<< Engravers Network has 1000gm bottles of 6000 for $532.10 --