Printer? Epson EcoTank ET-2800
ink? Epson Ink.

The forum is full with similar threads, but here are the facts once more:
a) Dye based inks are not good for t-shirt transfers.
b) Pigment inks are not all the same.

You could just refill your printer with Epson T542 ink bottles.
Not necessarily the best ink for the job, but it is the right type of ink, and you can buy it from a local store.
You just have to make sure the printer is used regularly, otherwise it will clog.

 

I know there are folks that run T542 ink in the ET-2800 / ET-2803 printers. I have both, the ET-2803 is set up for Sublimation, don't I need to run out / empty the ink tanks first? My ET-2800 is 2.5 years old and the ink levels are still above 50%.

Likewise, if there is a way to get good quality results using sublimation on dark fabrics, particularly cotton, I wouldn't need to use the 2800 for anything heat transfer related, just for stuff like stickers, documents etc...

 

Dump/suck the ink out of the 2800. Put in a pigment ink. T542 is probably the easiest path to a pigment ink, but it will yellow at bit when pressed, so one needs to tweak the settings to cut back on Y. Else one can get a 3rd-party pigment ink that is made to be heat pressed, so won't shift color balance ... but I'm not sure what the best 3rd-party options are at this point.

Anyway, what do you need the 2800 for if the ink in it can't be used for transfers? Dump the useless ink.

Sublimation must have a white substrate, be it a white polyester garment or a white "sticker." In the latter case one is not sublimating the garment, but the sticker, so nothing gained over a pigment based sticker, yes?

Pigment will likely also be better for stickers (not referring to garment stuff this time).

 

I didn't know it had to be white...

It doesn't. The garment just has to be lighter than the ink. So black on a red shirt will work. Sublimation ink is transparent. So once you start mixing ink colors with shirt colors the final ink color will end up not what you expected.

I am seeing some 3rd party pigment inks available but no clue which is good and which stinks

Stick with Tabob's recommendation and use Epson.

 

Sublimation must have a white substrate, be it a white polyester garment or a white "sticker." In the latter case one is not sublimating the garment, but the sticker, so nothing gained over a pigment based sticker, yes?

Likewise, if there is a way to get good quality results using sublimation on dark fabrics, particularly cotton, I wouldn't need to use the 2800 for anything heat transfer related

Switching to pigment ink will not solve the dark garment limitation.

The only way you can print opaque colors on a dark garment, is screen-printing.
All other methods require some type of a white base, and the same apply for sublimation.

I knew it had to be a light color for sublimation, I didn't know it had to be white...

You can of course print black ink on a light color garment, because black will cover all other colors.
If you try printing yellow ink on a blue garment however, the result will be some shade of green.

 

So the dark fabrics heat transfer sheet provides the white underlayment as it were. The sublimation setup so far has only been used to print on white substrate per the MFG... Which is no surprise.

I have been watching some videos on how to empty / clear out the ink from my ET-2800. Looks like a bit of a nuisance process, but may be worth it in the long run...

 

So the dark fabrics heat transfer sheet provides the white underlayment as it were.

Correct, and there are a few of them that work well with sublimation.
Examples:
FOREVER Subli-flex 202 works really well for typography and vector type designs.
FOREVER Subli-Flock Also works really well, especially if you want the flock feel.

 

I think we are on the same, if not page, chapter of the book at least...

 

I am printing with an Epson ET-2803, so I would need 8.5x11 or 8.5x14 (US Letter or US Legal). I am seeing 10pk of 8.5x11 for $32.99 is the lowest I have seen. Assuming it works out the way I want a 100pk is $219.99. Never used HTV Sublimation before, not sure of the quality of the end product but would be an expense I would have to factor in while pricing...

As far as "A" paper sizes, My printer can print A4, which is just slightly narrower, and longer than 8.5x11 US Letter

 

I am seeing 10pk of 8.5x11 for $32.99 is the lowest I have seen.

Quick google search... $25 for 10 ($2.50 per sheet).