Industry Trends

7 Questions I Wish I’d Asked Before Buying Brother MFC-L3720CDW & Ink Cartridges

The Mistakes That Made Me Write This

I've been handling office equipment for a mid-sized real estate agency for about 4 years now. In my first year (2019), I made a series of painfully stupid decisions ordering Brother toner and supplies for our new MFC-L3720CDW. The highlight? Ordering 50 black ink cartridges for a color laser printer that doesn't use ink (ugh). That's $1,200 worth of product I couldn't return because I'd opened the box.

Since then, I've personally made and documented about 15 significant mistakes costing roughly $4,200 in wasted budget. Now I maintain our team's equipment checklist. If you're looking at a Brother MFC-L3720CDW, or stocking up on Brother black ink cartridges, here are the questions I wish I'd known to ask.

1. What's the exact toner cartridge model for the Brother MFC-L3720CDW?

This is embarrassingly simple, but I got it wrong. The MFC-L3720CDW uses the TN-227 or TN-227XL toner series (standard vs. high-yield). It absolutely does not use the TN-223 or TN-760 series, which are for other models. I once ordered TN-223 because the online store said 'fits Brother printers.' One printer, three completely wrong cartridges (note to self: never trust 'compatible' lists without cross-checking the manufacturer sku).

Per Brother's official website, the exact breakdown is:

• Standard black toner: TN-227BK (~3,000 pages)
• High-yield black toner: TN-227XLBK (~4,500 pages)
• Standard color (C/M/Y): TN-227C/M/Y (~3,000 pages)

Don't ask me why the high-yield black is an XL designation while the color cartridges are just standard. It's annoying, but that's the system. If you're searching for 'Brother black ink cartridge' for this model—stop. It's a laser printer. It uses toner. That confusion alone cost me half a day of research.

2. Can I use generic (third-party) toner in the MFC-L3720CDW?

Technically, yes. Should you? In my experience, probably not for critical work. The MFC-L3720CDW uses a drum and toner system. The drum unit (DR-227) is separate, which means if a third-party cartridge leaks or has poor quality, it can damage the drum. The drum costs about $130 to replace. Saving $15 on a cheap TN-227 knockoff isn't worth the risk (I learned this the hard way—saved $80 on three cartridges, ended up replacing a drum for $130 plus a wasted weekend reprinting).

Here's something vendors won't tell you: Brother's firmware occasionally receives updates that can flag non-OEM cartridges and refuse to print. It's not universal, but it happens. If consistent quality matters, stick with Brother-branded TN-227 cartridges.

3. Wait—does the MFC-L3720CDW use 'ink' or 'toner'?

Frustrating question, right? It uses toner. It's a color laser printer. But the confusion is real because Brother sells both laser printers and inkjet printers. If you search for 'brother ink cartridges' on Google, you'll see the MFC-J series (inkjet). The MFC-L series (laser) uses toner cartridges.

I still kick myself for not reading the 'Printing Method' spec line in the Quick Setup Guide. It clearly says 'Color Laser.' If I'd paid attention, I wouldn't have ordered an ink cartridge for a laser printer. The lesson: open Brother's official product page, check the 'Printing Method' line, and buy accordingly.

4. Can I print custom envelopes for the Ryder Cup 2025 event?

Yes, but it's tricky. The MFC-L3720CDW has a manual feed slot (not a standard envelope tray). For large envelope runs—like printing Ryder Cup 2025 envelopes—you'll want to bypass the automatic feeder if possible. The standard tray has a slight curl issue on certain envelope stock (I discovered this on a $3,200 order of custom event envelopes).

According to USPS (usps.com), standard large envelopes (flats) are measured between 11.5" x 6.125" minimum and 15" x 12" maximum. The MFC-L3720CDW can handle up to 215.9 x 355.6 mm (8.5" x 14") for its manual feed—that fits most letter-size flat envelopes fine. But for anything larger, you'll need a dedicated printer. For the Ryder Cup envelopes, I'd recommend:

• Stick to letter-size (A4) or smaller
• Use the manual feed for best alignment
• Test-print on plain paper first (I cannot overstate this—I ruined 50 envelopes once because I skipped testing. Ugh.)

5. Can I print on custom fabric labels or an Attico tote bag?

This is where people get tripped up. The MFC-L3720CDW is a standard paper printer. It prints with toner powder fused onto paper at high heat (about 400°F). If you're trying to print on an Attico tote bag (canvas, cotton, synthetic fibers), the answer is probably not. The heat might damage the bag, and the toner won't adhere to fabric like inkjet transfer paper would.

For fabric items, you'd want a dedicated sublimation or DTG (direct-to-garment) printer. Brother happens to sell those too (like the GTX series), but the MFC-L3720CDW is not one of them. Check the product line clearly: this model is for paper documents and cardstock—not canvas totes.

The surprise wasn't that the printer couldn't handle it. It's that the online forums said 'just use transfer paper.' We tried that—on an Attico tote—and the result was a blurred mess. Total loss: $40 for the bag plus $20 for wasted transfer sheets. Lesson: fabric printing needs heat press and proper ink, not laser toner.

6. What should I do if my Brother ink cartridges (toner) dry out?

Wait—toner doesn't dry out (it's a dry powder). But inkjet ink does. The search term 'brother ink cartridges' pulls up inkjet models. If you meant toner for the MFC-L3720CDW, toner has a shelf life of roughly 2-3 years if sealed, but it doesn't 'dry out' like ink. If you have a genuine black toner cartridge for this printer and it's not printing, shake it gently (seriously—I finally figured this out after three wasted cartridges). Toner powder settles. Shaking redistributes it.

If that doesn't work, check the drum unit. The drum can get scratches or residue. Replace the drum (DR-227) before buying a new toner cartridge. I've saved about $300 by troubleshooting the drum first instead of panic-buying new toner.

7. Is there a cheaper way to get Brother black toner?

The high-yield (TN-227XLBK) cartridge offers about 50% more pages for a 20-30% price increase. In my experience, that's usually the most cost-effective option if you print over 1,500 pages a month. For lower volume, stick with standard. Also, Brother has a 'Recycle and Rewards' program that gives you a free return label and sometimes a discount on your next purchase. It's not enormous savings, but it's something.

Final note: always check the price per page (PPP). High-yield black TNs give you about 2.2 cents per page vs. standard at roughly 2.6 cents per page. That difference adds up—on a 10,000-page year, it's about $40 saved (note to self: track this better next year).