I have an Oki laser printer. It's small, lightweight, and has the capability of easily printing envelopes.

I use ordinary #10 envelopes and the machine works flawlessly except ... the envelopes often come out nicely printed, but sealed. Apparently the fuser will seal the envelope, making it useless.

I wound up slipping a piece of paper between the flap and the body and it worked fine, but that's probably not practical for printing quantities.

I know there are people here who print a lot of envelopes, so I'm wondering if they have the same problem and how to they handle it? Is it possible my envelope stock is old and not suitable? Any suggestions?

I always found putting envelopes in a laser printer resulted in bent/curved envelopes.

If I have a lot to print I find sheets of laser labels work. Individual letters I manage to use window envelopes with the address in the correct place in the letter, or I also have a Dymo Labelwriter connected to my PC which has Address and File labels loaded.

Most laser printers need you to open the back guide panel for printing envelopes. The combination of the heat and pressure from rolling envelopes to the output tray seals them. If you open the back panel (or wherever it is on your particular model) so that envelopes can travel in more or less a straight line, you'll have better results.

That was always a problem with my (almost 20-year-old) Lexmark Optra R. Some types of envelopes seemed to be more susceptible than others, and it was pretty random. I suspect climate had something to do with it as well -- higher humidity days obviously worse than in low humidity winters.

The older enveloper stock might actually be in your favour, IMHO, as the glue will be wettest when the envelops are 'fresh' so to speak. .

I use the envelopes with the strip that covers the adhesive. They wrinkle a bit as do all envelopes that go through the printer, but they never seal from the heat or pressure.

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I use the same laser printing envelop solution.

What's an envelope?

The same as an onvelope.

Yeah, I've never even tried to run an envelope through, I would expect trouble from the fuser. I just print separate labels. I have a Brother QL-570 label printer for such things--while it would be expensive for high volume use (use sheets of labels for that) it excels at printing a label or two.

I have a Lexmark laser dual bin printer and print labels for envelopes without windows or envelopes larger than DL, i.e. A-4. I found running envelopes thro' the machine skews them, which can be expensive in wasted envelopes.

I also use window envelopes for 50% of our mail.

I have used several machines for this over the years and have found the following:

Most inkjets don't have a robust enough mechanism for envelopes in any quantity, however they run cold so press-seal envelopes will work IF they run through straight.

I almost invariably run into troubles if the printer is tray fed - they just don't like curling around rollers. So go for a printer that allows rear fed envelopes

DL and C5 work fine in pretty much any printer. C4 and upwards can be problematic. C4 is often ok, but it is both wider and longer than A4 so might not fit. Any of the larger sizes (for example the slightly larger version (I can't remember the number) designed for large stacks of A4) and gusseted versions can cause big problems.

Long story short I ended up with a very robust HP Laser Printer with a specific envelope stacking tray at the back. I'm no longer in that business so can't tell you the number, but it worked great, using Peel and Seal.