The chips are region dependent (PGI-1200 vs 1500 etc), the inks not, you can buy it where you want (IMO almost any pigment ink will work in the Maxify).
Use the octopus-office.de video for refilling OEM cartridges. But since you don't know how many ink you need to top up, weigh the carts.
All OEM carts are internally the same, the XL are full, the other only half.
@The Hat 's tools (a cut-off needle) should work, PRO-1 carts have a similar ink outlet.
You can determine it adding the declared ink volume to the empty weight.
XL are 35ml for BK and 12ml for the colors.
As you can see on the octopus-office.de site the ink bags may only be half full since in the center there is an air vent (ending in a recessed second exit above the ink outlet).
Some sites suggest to block this exit while refilling but I did not found any advantage.
Just keep the cart vertical and alternate suck and push until all ink is in.
This is what I found concerning the weight of Canon OEM PGI-2500XL cartridges :
PGI-2500XL black empty : 62 gr - full : 135 gr
PGI-2500XL C/M/Y empty : 47 gr. -full: 68gr
Take into account that pigmented ink is a bit heavier than water so 1 ml of ink isn't exactly 1 gr.
Therefore, to refill an empty OEM PGI-2500XL black cart up to 135gr,. you need 69-70ml of ink (equal to 73gr)
I use Inktec to refill. Those figures may differ a bit with a different brand of third party ink.
@palombian, the ml values you give on post # 15 are for PGI-1200XL cartridges?
Wow, big difference in size between PGI-1200XLs and PGI-2500XLs cartridges.
I have the ARC chips and ink. I'm trying to build a tool for refilling following @The Hat 's tools (a cut-off needle) for PRO-1 carts. However my attempt doesn't fit, its too loose.
I tore the ink output port from a PGI-1200 to have a closer look. You can see the back of the ink port has many little holes and a slit for ink flow. Looking down the throat of the port there is a step down in diameter. This step down is actually a silicon(?) plug with the holes and slit molded into it.
My question is, does this refill tool need to seal to the silicon plug or can the tool just seal to the larger outside edge of the port? As you can seen here a naked syringe without needle fits the outside edge. But would this leak and create a mess during refills? The loose plastic seal may cause leakage.