weird banding in white area

[bigben]

I have an HP L26500, using a new synthetic paper and have created my own profile. For some reason if I print something with heavy covering beside a white part. I will have fine banding in the white part where there supposed to have no ink. It's not very noticable, but I can wipe the banding with my finger.

Here is the best picture I could take. You can barely see it, but it is more noticeable in person. I've never experienced this before. What could be the problem and solution?

 

[DerbyCitySignGuy]

So when you print pure white next to a block of color, for instance, the white has a slight hue to it the first few passes?

Could be a static/overspray issue? Some of the CMYK inks getting on the white heads and creating a slight off color for the first few passes. That would be my best guess.

 

[bigben]

So when you print pure white next to a block of color, for instance, the white has a slight hue to it the first few passes?

Could be a static/overspray issue? Some of the CMYK inks getting on the white heads and creating a slight off color for the first few passes. That would be my best guess.

This is exactly what happen and is exactly what I suspect (static/overspray). How can I manage this?

 

[DerbyCitySignGuy]

This is exactly what happen and is exactly what I suspect (static/overspray). How can I manage this?

I know you said it's paper, but can you treat the area with an anti-static spray before printing (easier said than done on a roll to roll machine)?

Short of keeping your print room at 70 degrees and 50% humidity, I've never found a perfect way to deal with static.

 

[BIG EASY DOES IT]

I don't think it's overspray. If it looks like banding my guess would be optimizer. Optimizer is clear but certain substrates you can see it. Also if you have a vector that is colored white there is a lot of times where the HP will lay down optimizer but no color. My guess is you have a banding issue with your optimizer head and you can see it in the blank areas.

 

[bigben]

I know you said it's paper, but can you treat the area with an anti-static spray before printing (easier said than done on a roll to roll machine)?

Short of keeping your print room at 70 degrees and 50% humidity, I've never found a perfect way to deal with static.

With the winter right now, it's very dry in the shop. This is why I think it is a static problem. I've just printed the same thing to a regular vinyl and there was no problem at all.

I don't think it's overspray. If it looks like banding my guess would be optimizer. Optimizer is clear but certain substrates you can see it. Also if you have a vector that is colored white there is a lot of times where the HP will lay down optimizer but no color. My guess is you have a banding issue with your optimizer head and you can see it in the blank areas.

I can't be the optimiser. My latex model (L26500) don't have the optimizer.

 

[DerbyCitySignGuy]

With the winter right now, it's very dry in the shop. This is why I think it is a static problem. I've just printed the same thing to a regular vinyl and there was no problem at all.

Yeah, paper sucks up moisture too. Run a humidifier full blast while printing?

 

[bigben]

Yeah, paper sucks up moisture too. Run a humidifier full blast while printing?

I will go buy one first and see what happen.

 

[Jay Grooms]

Yeah, paper sucks up moisture too. Run a humidifier full blast while printing?

and all night, and all weekend...... I don't think it'll ever warm up enough for us to turn our humidifiers off. I just love living in a cold dry tundra......