Blue envelopes on Inkjet Envelope printer

[jwheeler]

We have a Postmark RapidColor 1170 Pro inkjet envelope printer. This is the same rebranded engine as the iJet 1175C

We're trying to run some #10 Domtar blue envelopes (a light/pastel blue) and they keep coming out blank. We switch to white envelopes and they print just fine. I'm assuming this means the laser eye that senses the envelopes entering under the print head can't see it against the blue transfer belt. The blue of the paper is much lighter than the transfer belt as you can see with the images below. Does anyone know if there is a setting we can turn on/off that would enable this to work?

 

[jwheeler]

I should have tried ChatGPT first...it pointed me to this post from 2023 by @Make_It_So which says to use the "Teach" button on the sensor.

More details from ChatGPT:

What's interesting is that the iJet 1175 manual specifically describes this exact situation. The machine uses a TOF (Top Of Form) sensor that learns the difference between the belt and the media. The manual states that when you change stock and "the system no longer prints," you may need to teach the sensor again.

What I would try first:

1. Remove all envelopes from under the sensor.
2. Make sure the sensor sees only the blue conveyor belt.
3. Press the Teach button on the TOF sensor.
4. The display should show "2-nd".
5. Place one of the blue Domtar envelopes under the sensor.
6. Complete the teach procedure.

The manual specifically says changing stock can require reteaching the sensor, and loss of printing is one of the symptoms.