I haven't had these 108 or 115 inks in my hands, that's probably rather new products brought into the market by Epson.
Adding inks wtih additional numbers allows Epson to do different pricing for the same ink - the108 ink is titled as a
Claria Premium ink for the L8160 which is a white printer model practically identical with the ET-8500 and its 114 inks, but the 115 inks are just more expensive than the 114 or 106 inks (which may vary over time) And pricing in one country is not the same for the same product in other countries.
And Epson brought the L8050, L18050, L8100 printer into the market apparently not so long ago with the 108 inks .
I'm not following all twists and tricks by Epson and Canon.
Epson is marketing printers as the LXXXX models primarily in the eastern EU part, and with correspondig ET-xxxx models in the western areas. . But some models are sold even in parallel in Germany - at different prices - and it's up to the customer to understand all that.
If you want to go for an ink slightly more stable than all these above you go for the inks for the Surelab D500 printer,
the Ultrachrome® D6r-S inks in bottles as the T54C inks. These inks have been available since a long time but only in cartridges up to 700ml , with the exception now with the T54C bottles.
I'm not chasing all these different - or same - inks anymore, I just run my ET_8550 with 106 inks and the T3100X with a pigment mix. And I'm testing a new paper once in a while.
