I should know the answer to this; I'm embarrassed to bring it up. Anyway--here's my question. My Canon BJC2000 inkjet printer occasionally runs out of ink. I recently found online a great sale on 'BJC2000 compatible' ink cartridges. But each of the new cartridges are about one third the size of the original one.

Am I missing some sort of attachment that holds the replacement ink? Are they inserted differently.

Any help you could give me would be most appreciated.

They may have sent you the wrong ones. It happens. Check your invoice for a return address and send them back. A 'compatible' cartridge should fit the printer exactly the same way as an original does.

I agree - I thought most places just used old cartridges that they refill?

I looked at two suppliers and both cited using OEM (Original Equipment Manufacturer) cartridges for their product. One though was very hard to pick the BJC cartridge and not one for a different printer type. Make sure the part number you ordered is the number for the BJC.
If buying toner is something you do often, you might want to invest in a cheap laser printer. You only get B&W (from the cheap ones) but that is sufficient in most uses and save the expensive coloreds for when absolutely necessary. I've gotten from two Laser toner cartridges over 5 reams of printing done. The Cannon would have cost near a thousand dollars for that amount of ink. And I got the first cartridge with the printer free and a recycled cartridge cost me $75. So figure: couple hundred for a laser printer or a thousand for ink jet cartridges.

It might be possible for the cartridges to be a smaller physical size but still clamp in and work OK. For instance, it's possible to get two different sizes of black ink cartridges for some printers. Difficult to say whether this could be the case with the cartridges you have without owning the printer.

I've done an Internet search but I can't find anything about compatible cartridges for that printer being smaller in size. If you type BJC-2000 compatible ink cartridges into a search engine, there are many sites showing pictures of them. I know this doesn't give an idea of the physical size but do the replacement cartridges look the same shape as those? So long as they look as if they could fit (maybe just narrower than the originals), they may still be the right ones to use.

The correct numbers for the cartridges look to be BCI-21C for the colour cartridge and BCI-21B for the black one. Are those the numbers on the cartridges you have? If uncertain about them, I think perhaps the best action would be to make a phone call or send an e-mail to the suppliers. Voice concerns about the smaller size and ask for reassurance that they have sent the right ones.

Thank you so much for the suggestions. I'll be on the phone first thing Monday morning.