Banding in (deep) blue skies: disappears after 1 or 2 pages

[pharmacist]

Could someone tell me how this can happen. When I startup my printer after several days, the prints have a slight magenta banding in blue skies, especially in deep blue skies (hardly noticable in lighter blue skies). But after printing several pages, the banding disappears suddenly. The prints hereafter are all OK. It looks like there is feeding problem the first moment after a period of standstill. Is this normal ? Strangely enough the nozzle check printouts are 100 % OK. No colour dropouts what so ever. The problem is more pronounced when using the papersetting: Photo Paper Pro (less or completely absent when using the setting: Glossy Photo paper)

It is my Canon i9950 A3+ printer who has this problem.

 

[pharmacist]

Could it be possible that the inkflow is to low to pump up the ink fast enough to blend well ? Maybe the cyan is not flowing fast enough when the print speed exceeds a critical point, causing banding. I tried again with both photo paper pro printing (faster printing) and glossy photo paper (slower) and used a picture with darker area's. What I found out is that the faster printing mode: Photo Paper Pro setting causes particular banding (which colour I don't now, but visible lighter bands) in the darker area's like deep blue skies and dark colours like dark grey/black shadows. This is absent when using Glossy Photo Paper setting (slower and using microweaving ?).

For the moment I have to use the Glossy Photo Paper setting to avoid banding in dark area's, but I would like to use the PPPro setting as this is much faster when printing several pictures at a time.

I have filled all my original Canon cartridges with Hobbicolor ink now with the german Durchstich-method (pierced hole left open) and I like the colours very much. Sadly the banding still exists when using the PPPro setting......

Just have a look at the pictures beneath to see the difference:

 

[ghwellsjr]

I could be wrong, but it appears to me that the banding is in the "good" prints also, just closer together so it is less obvious. You "good" printout was done with an 8-pass setting and your "bad" printout was done with a 4-pass setting which would put the offending bands twice as close together. It's really hard to see the banding anyway, so I could be all wrong.

BTW, to see what type of printing is done for each paper/quality setting, see this post:

http://www.nifty-stuff.com/forum/viewtopic.php?pid=9079#p9079

The fastest decent printout is with the 3-pass Photo Paper Plus Glossy in the Draft quality. It is unique among the settings because each pass itself looks like it was made with several passes. Try it and see if you like the speed. You will probably still have the banding problem, but when you get it fixed, it may be a setting you'll like.

 

[pharmacist]

Yes, there is banding in the "good" printing but closer together, but less pronounced or totally absent in the lighter areas of blue sky. Could it be a problem with the ink not flowing fast enough when printing large amounts of the same colour ? Since this theory is strengthened by the fact that the faster PPPro setting for printing is more pronounced than the the Glossy Photo Paper setting ? And as you can see the other areas are completely well printed. How can I test if this is caused by an improper inkflow from the cyan/photocyan cartridges ?

 

[Grandad35]

It looks like there is feeding problem the first moment after a period of standstill. Is this normal ?

1. Does running a cleaning cycle before printing fix the problem?
2. Pull each cart (one at a time, putting it back before removing the next cart) to see if there is a small puddle of ink on each ink pickup. If a pickup is dry, the cart may be starving the pickup.
3. How many times have you refilled these carts?

 

[pharmacist]

Hi grandad35,

1. It does not
2.there is a small puddle on the ink pickup with all the colours
3.It is actually the first time of refilling of the original Canon cartridges: for the sake of uniformity I removed all the original ink still remaining in the cartridges and replaced them with UW-8 ink from Hobbicolors.

Today I tried the setting of Photo Paper Pro with manual setting and set the quality setting to 1 and halftoning to diffusion: whow the quality was astonishing and no more banding at all even in large deep blue sky area's !!! The setback was the dramatic drop in printing speed. It seems that the automatic setting for Photo Paper Pro when set to print quality = high is actual quality setting 2 and not the finer setting 1.....

The Glossy Photo Paper Extra setting gives me excellent print quality too, without any banding in blue skies and was actually about the same speed as Photo Paper Pro at the standard high quality setting.

I came to the conclusion I have to use the highest print quality (setting to the quality manually to 1) to completely remove banding in dark area's of the same colour. Does someone have similar experience with this problem ?

 

[Grandad35]

pharmacist,

It sounds like your carts are functioning properly, but that some of the nozzles have to "warm up" before they expel the ink from all of the nozzles. I had this same thing happen (also on Cyan) on a set of 3rd party prefilled carts that I tested over 2 years ago. The problem was eliminated by switching to bulk ink and refilling.

Any "good" photos should be printed at the highest quality setting. Consider how difficult (and costly) it would be to make each nozzle on the print head perform exactly the same as every other nozzle. To keep the costs down, some variation between nozzles is accepted, and the printer overprints the same area multiple times by advancing the paper by 1/8 of the print head's width for each pass. In this way, even a few clogged nozzles will still result in 7/8 of the desired ink coverage where the nozzles are clogged. This obviously takes longer to print.

Some of the "plain paper" settings advance the paper by a full print head width for each pass of the print head. This is obviously faster, but any nozzle problems will stand out like a sore thumb.