Can Canon PG-445XL and CL-446XL Cartridges Be Refilled? Refill Holes, Vacuum Filling, and Regional Cartridge Numbers Explained

Question

I watched your detailed guide about refilling Canon PG-275, CL-276, PG-275XL, and CL-276XL cartridges. I use Canon PG-445XL and CL-446XL cartridges and would like to try your method when they run out of ink.

Will the same refill method work with my cartridges? Will making the refill holes larger affect printing?

I previously took my cartridges to a repair technician who refilled them without opening the cartridge or visibly enlarging the air holes. I cannot see any signs showing where ink was injected. How could the technician have refilled them without making a noticeable hole?

Answer

Yes, the general refill method shown for cartridges such as the PG-275XL and CL-276XL can also apply to Canon PG-445XL and CL-446XL cartridges. These cartridges belong to Canon's FINE cartridge family, in which the printhead, nozzles, ink chamber, sponge, and electrical contacts are incorporated into the cartridge itself.

Canon sells closely related cartridge families under different model numbers in different regions. Examples commonly encountered include:

• PG-145 and CL-146 in parts of Central and South America

• PG-245 and CL-246 in North America

• PG-345 and CL-346 in some markets

• PG-445 and CL-446 in Russia and certain neighboring markets

• PG-545 and CL-546 in Europe

• PG-645 and CL-646 in Australia and Oceania

• PG-745 and CL-746 in South and Southeast Asia

• PG-845 and CL-846 in China

• PG-945 and CL-946 in Korea

The regional numbers do not mean that every cartridge in the list is universally interchangeable. The physical keys, electrical identification, chip programming, ink capacity, and printer firmware can differ. Therefore, you should always purchase and use the cartridge number specified for your exact printer and sales region. However, their internal construction and the basic principles used to refill them are often very similar. Canon's official regional documentation confirms that PG-245/CL-246, PG-545/CL-546, PG-645/CL-646, and PG-745/CL-746 are used as corresponding black-and-color FINE cartridge families in their respective markets.

Will a Larger Refill Hole Affect Printing?

A moderately enlarged refill hole normally has no direct effect on print quality because the hole is located on the upper cartridge cover, while printing occurs through the microscopic nozzles on the bottom of the cartridge.

The refill hole does not control image resolution, nozzle firing, color placement, or electrical communication with the printer. Its main purpose during refilling is to provide access to the sponge and internal ink chamber.

However, the size and treatment of the hole can indirectly affect cartridge performance if the opening is made excessively large or left improperly sealed.

A refill hole may cause trouble when:

• The hole is so large that the cartridge cannot maintain normal internal pressure.

• Ink is injected too quickly and floods the air passages.

• The hole is sealed completely airtight when the cartridge requires ventilation.

• Loose plastic debris falls into the cartridge.

• The drill or needle penetrates too deeply and damages the internal sponge.

• Ink leaks from the opening while the cartridge is being handled or installed.

For most refill procedures, the hole only needs to be large enough for the refill needle to enter without excessive resistance. A small drill bit, heated needle, or appropriate cartridge tool can be used, but care must be taken not to push plastic particles into the sponge.

After refilling, the opening may be covered with a label, plug, or suitable tape, depending on the cartridge design. Do not automatically create a completely airtight seal. Canon cartridges use carefully designed air channels to replace the volume of ink leaving the cartridge. Blocking the ventilation path may prevent ink from flowing, while leaving an unnecessarily large opening may allow leakage or excessive evaporation.

Why Might There Be No Visible Refill Hole?

The technician most likely used a vacuum-filling method. With this technique, the cartridge does not necessarily need a large new hole drilled into the top.

A vacuum system reduces the air pressure inside or around the cartridge. Once the trapped air has been removed, ink is introduced or released into the cartridge. As atmospheric pressure returns, the pressure difference helps pull ink into the sponge and internal chamber.

Depending on the equipment, the technician may have accessed the cartridge through:

• The existing factory vent

• A concealed point beneath the original top label

• The outlet or nozzle area using a sealed adapter

• A specialized cartridge holder connected to a vacuum pump

• A very fine needle inserted through an existing air-channel opening

If the original label was lifted carefully and then placed back in its original position, you may not see any evidence that the cartridge was accessed. A tiny needle puncture can also close around itself or remain nearly invisible beneath the label.

Commercial vacuum-refilling machines were once used widely by cartridge refill shops. Some repair technicians still use these machines or homemade vacuum chambers. The cartridge is placed in a sealed fixture, air is removed, and ink is then drawn into the internal sponge. This can refill the cartridge evenly while reducing the likelihood of large air pockets.

The technique can look mysterious because no obvious hole remains, but it is based on pressure control rather than an invisible injection method.

Can Ink Be Injected Through the Nozzles?

Ink can sometimes be drawn into or through a cartridge from the printhead outlet using specialized adapters, but directly forcing ink backward through the nozzles is risky.

The nozzles and internal ink pathways are delicate. Excessive pressure can:

• Separate internal filter layers

• Damage the nozzle plate

• Cause colors to cross-contaminate

• Flood the electrical or heater area

• Create permanent nozzle failure

• Push debris deeper into the cartridge

For this reason, a controlled vacuum process is different from simply pressing a syringe against the nozzle plate and forcing ink backward. Professional fixtures regulate the pressure and seal around the appropriate outlet areas.

Refilling the PG-445XL Black Cartridge

The PG-445XL contains pigment-based black ink. Internally, it uses an absorbent sponge that distributes ink toward the printhead.

When refilling it:

• Use ink specifically formulated for Canon thermal inkjet pigment-black cartridges.

• Insert the needle into the sponge rather than leaving it directly beneath the top cover.

• Add ink slowly so the sponge has time to absorb it.

• Stop if ink begins collecting around the vent or leaking from the nozzles.

• Allow the cartridge to rest before reinstalling it.

• Blot the nozzle plate gently on a clean, lint-free, damp paper towel to confirm ink flow.

Do not assume that the XL cartridge can accept an unlimited amount of ink. The correct capacity depends on how empty the cartridge actually is, how much ink remains in the sponge, and whether the cartridge has dried internally.

Overfilling can cause dripping, smearing, contamination inside the printer, or ink buildup around the cartridge carriage.

Refilling the CL-446XL Color Cartridge

The CL-446XL is more complicated because it contains three separate color chambers, normally cyan, magenta, and yellow. Each chamber has its own sponge and ink pathway.

Before adding ink, confirm the location of each color chamber. Do not rely solely on the color of the opening or the arrangement used by a different cartridge model. A wooden toothpick or clean needle can be inserted lightly into each sponge to identify its existing ink color.

Use a different syringe and needle for each color. Even a small amount of contamination can cause incorrect colors. For example, introducing cyan ink into the yellow chamber may produce green-tinted output until the contaminated ink has been consumed or removed.

Add the ink slowly. Color cartridges have relatively small chambers, and overfilling one chamber can allow ink to migrate into another chamber or leak through the nozzle plate.

Airflow Is Essential

Canon FINE cartridges do not operate like completely sealed bottles. As the printer consumes ink, air must enter through the cartridge's ventilation system. This balances the internal pressure and allows ink to move toward the nozzles.

If the vent is blocked, the cartridge may initially print and then gradually fade or stop. Removing and reinstalling the cartridge may temporarily restore printing because the movement changes the pressure, but the problem will return.

If the opening is too unrestricted, the cartridge may leak or deliver too much ink. The objective is not simply to make a large air hole. The objective is to preserve the cartridge's intended pressure balance.

When replacing the top label, make sure it does not cover the original serpentine air channel incorrectly. A label positioned a few millimeters away from its original location can block an important section of the vent.

Why a Refilled Cartridge May Still Appear Empty

Refilling adds physical ink, but it usually does not reset the cartridge's electronic ink-level record. The printer may continue to display a low-ink or empty-cartridge warning.

On many Canon printers, printing can continue by holding the Stop, Resume, or Cancel button for approximately five to ten seconds after the printer reports that the ink has run out. The exact button and procedure vary by printer.

This action generally disables ink-level monitoring for that cartridge. It does not reset the cartridge to show as full. You will need to monitor print quality manually and refill before the sponge becomes completely dry.

Do not continue printing when the cartridge is producing blank pages or severely faded output. Canon FINE cartridges use thermal nozzles, and the ink helps cool the heating elements. Running the cartridge without sufficient ink can overheat and permanently damage the integrated printhead.

When Refilling May Not Restore the Cartridge

A cartridge can contain enough ink and still fail to print correctly. Possible causes include:

• Dried ink inside the nozzles

• Air trapped between the sponge and printhead

• A sponge that has hardened after extended storage

• Damaged electrical contacts

• Burned nozzle heaters

• Delamination or internal separation

• Cross-contamination between color chambers

• A worn or electronically rejected cartridge

If the cartridge has been allowed to remain empty for a long time, refilling alone may not restore it. The sponge can dry and stop transferring ink effectively to the printhead.

A cartridge that repeatedly overheats, produces missing nozzle patterns after cleaning, or is not recognized by the printer may require replacement. Refilling extends the useful life of many cartridges, but these cartridges are not designed for unlimited reuse.

Recommended Approach for Your Cartridges

You can use the principles demonstrated in our PG-275XL and CL-276XL guide for your PG-445XL and CL-446XL cartridges, but first verify the chamber arrangement and refill capacity for your specific cartridges.

A small, properly positioned refill hole should not affect printing. The larger concerns are overfilling, blocking the air channel, using incompatible ink, contaminating the color chambers, or allowing the printhead to run dry.

The technician who previously refilled your cartridges most likely used the existing air path, accessed a concealed point beneath the label, or used a vacuum-refilling machine. Vacuum filling can leave little or no visible evidence when performed correctly.

Addressing printer and cartridge problems can be complicated because many diagnoses require direct observation, testing, and hands-on work. For that reason, we are unable to provide individualized remote troubleshooting or repair support. We do offer in-person evaluation and repair through our local printer diagnostic and repair facility [https://bchtechnologies.com/printer-repair-service]. Because demand is high, the service operates on a first-come, first-served basis, and it may take several weeks before an appointment or drop-off opening becomes available. Our services can cover an entire printer or, in certain cases, a specific component, with instructions provided for submitting the equipment. We also recognize that professional repair is not always the most economical option. Therefore, we strongly encourage self-help through careful online research. A good place to begin is YouTube or the homepage of the BCH Technologies YouTube channel [https://youtube.com/@bchtechnologies]. Use the search icon near the "About" section on the right side of the channel menu to search for your cartridge number, printer model, or symptom. We receive dozens of questions each day asking whether we have covered particular subjects. Since we have produced repair and refill videos for more than nine years, it is difficult to remember every individual video. YouTube's search function is usually the fastest way to locate the appropriate material, and it may also recommend useful videos from other technical channels.

Thank you again for watching our video, supporting BCH Technologies, and sharing such an interesting question. We appreciate your curiosity about the vacuum-refilling process and hope this explanation helps you refill your PG-445XL and CL-446XL cartridges more confidently and safely.