Help Tips: The difference between HP "A" and HP "D" 
Cartridges and other refilling tips

Example: HP C6578A or HPC6578D 

If there is air in any of the nozzles, ink from one of the other nozzles can, by capillary action, be drawn across to the empty nozzle and contaminate the chamber. Also overfilling certain cartridges can cause cross chamber contamination. If the contamination is severe the cartridge may not be able to be repaired. In the case of slight contamination you can try letting the cartridge sit on a damp cloth overnight. The contaminated ink will be drawn out of the print head by capillary action. Run some cleaning routines to 
prime the cartridge.

What HP doesn't want you to know.

On the left (below) is a C6578D which is half filled (19ml/cc) with ink.
On the right (below) is a C6578A which is filled to (38ml/cc) capacity.

The D cartridge comes with most new Printers that HP makes. The C6578D cartridge retails for about $35 and the C6578A retails for about $60. So you think, "I will save money if I buy the C6578D", but you are only getting half the ink.

Well, what if I want a remanufactured cartridge, do I get a half filled cartridge or do I get a full cartridge?

Our remanufactured cartridges are filled to capacity (38ml/cc), and they retail for $22.95. 

So, the only difference between an "A" cartridge and a "D" cartridge is the amount of ink first placed in the cartridge by HP.

 

C6578D (left) Half Filled 19ml HP Filled Cartridge C6578A (right) Full 39ml Our Remanufactured Cartridge Side covers removed.

One of the biggest problems with the C6578 and C1823 is cross contamination. 

If there is air in any of the nozzles, ink from one of the other nozzles can, by capillary action, be drawn across to the empty nozzle and contaminate the chamber. Also overfilling certain cartridges can cause cross chamber contamination. If the contamination is severe the cartridge may not be able to be repaired. In the case of slight contamination you can try letting the cartridge sit on a damp cloth overnight. The contaminated ink will be drawn out of the print head by capillary action. Run some cleaning routines to prime the cartridge.

The picture shows how the yellow chamber went empty and the printer continued printing, so what happened,  the cyan ink  traveled to the yellow chamber causing cross contamination. You unknowingly fill the yellow compartment because it is empty, so when you go to reuse the cartridge you now have a chartreuse or green color coming out of your printer. So, of course you blame the ink that you used to refill. When in fact it is a problem with the construction of the cartridge itself.