I use an Eco Universal vacuum plus machine. I was filling some HP92 carts today. My cleaned carts weighed 20grams apeice. I am using BKP89 optimized ink.

I forgot to flip the "VAC" switch on for the first 2, set the timer to 28 seconds and they filled to 34grams. They both tested great. When the "VAC" switch is off and you press the "START" button, it sucks all the air out, then decompresses while it fills.

I noticed the switch near the end of my second fill and flipped it back on for the next cartridge. I also thought it'd be cool if I could get a straight 15 gram fill and a cartridge world australia weight chart I have says it can go to 36 grams. (This chart is usually a little high on the weights)

So I put the timer on 30 seconds and my next 2 fill overflowed and weighed 31 grams. So it seems to me that even though I can fit more ink the cart without a normal vacuum process, there should be more air in the carts and render them very streaky, but they weren't. Can anyone explain to me why this happened and why I should or should not put more ink in these carts?