Strange marks on prints


#1

I’ve made a series of prints and got some strange marks on them. I’m printing a panorama as a triptych, and on each of the three prints I’ve got a strange mark in the corner.

I first printed them as A4, and failed to notice it. How I didn’t I don’t know - my excuse is that I was focused on shadow detail and wasn’t paying attention to the highlights in the corners. I only noticed when I was framing the A3+ = 13"x19" versions. What a waste of ink and paper!

I’ve attached two images showing the problem. One shows the whole image, with the paper feed direction with a red arrow, and the problem area in a red oval shape. The second shows a close-up of the problem. I am printing on an R1900 with Epson Smooth Pearl using K7SE with the warm opaque black, so a second gloss coat is used. I’m on Windows 7, so using QTRGui.

Unfortunately I don’t know whether the problem during the first run with the inks, or the second run with the GO, as I didn’t notice until after the GO. This may suggest that it was after the GO, or I would have noticed. The gloss coating, when viewed from an oblique angle, looks ok, so it appears to be under the gloss.

I don’t know whether this is mechanical, from the printer, or an ink flow problem, or software related. It looks like it is mechanical, from the paper feed roller. It’s in the right position on all six pages. If this was the case, then it couldn’t have happened during the ink run because it’s on the wrong side for the paper feed roller. If it happened during the gloss run then I must have put all six pages in the printer the other way around, which is possible.

At the point when I noticed this, I needed to refill the carts to do further testing. This meant a head clean of course. I’ve since reprinted and re-glossed both the A4 & A3+ versions and all six pages seem ok. This might suggest that it was a strange clog problem, but it doesn’t look like it. I also had a bit of a play with the paper feed roller around this time, manually rotating it (probably not advisable), which may have unjammed it or something.

My best guess is that it did occur during the feed for the gloss run, with the paper feed roller getting stuck somehow and marking the print during the first part of the feed. My rotating the roller perhaps cleared it.

Have you ever seen this?

Yours confused

B.


#2

The problem has reappeared and it’s definitely the roller. :frowning:

One thing I forgot to mention that all prints were dried before the gloss coat went on. Some for 24 hours and some with a hair dryer for at least 5 minutes, usually more.

How do I stop the paper feed roller marking the prints during the gloss run? The roller doesn’t look dirty.


#3

Hi Brian~

This mark is caused by the 1/2 circle rubber paper feeder. When it takes the sheet, the rubber 1/2 circle grabs and rubs on the paper surface, which can mark or rub off the ink print. This can be an issue with all desktop printers, as they all have the same paper feed mechanics. As you’ve noticed, the paper feeder touches the sheet a few inches up on the right edge. What I have done to get around this is either leave a few inches top margin so the paper feeder doesn’t touch the image area, or a better solution is to attach a leader sheet to the paper, so the leader sheet is grabbed, and you don’t have to reduce the image size. We have some helpful Piezography glossy printing tips, including the leading paper strip, here: http://www.inkjetmall.com/tech/content.php?147-Piezography-Gloss-Printing-Tips

I hope this helps.
Please let me know if you have further questions or there’s anything else I can help you with.
Best regards~ Dana :slight_smile:


#4

Thanks Dana. There are a couple of things that still puzzle me.

First is that sometimes it happens and sometimes it doesn’t, on the same image on the same paper. I wonder why? Different drying?

Second is that some marks extend a long way into the print. On some 13"x19" prints, I already have a 1" border and would have needed at least an additional 2" to avoid the problem, i.e. a leader sheet of 3". On some A4 prints the length was variable, but one went as far as 3.5" from the edge of the paper Why the difference? Why so far?

It appears to me that the paper feeder is staying engaged with the paper too long, almost as if it is jammed into the position it uses when it’s feeding the paper and only retracts slowly. Is this possible? Does it work this way? That would explain the intermittent nature of the problem and the variable length of the mark.

Will cleaning the roller help, which is what I was expecting you to suggest? Doesn’t look dirty but it’s hard to tell.

How many times can I reuse a lead sheet? I.e. how many gloss coatings can I apply to it? (There are only so many scraps of the same sort of paper lying around.)

An extra 2"-3" of GO to be applied across a 13" sheet will increase my GO usage a fair bit, and I’m already using a lot. More GO refills means more head cleans means more ink wastage. The gloss printing is getting harder.

B.


#5

Yes, you should keep the printer clean, including the paper feed area, for the best function and results. The paper feeder touches the paper the least when it grabs the sheet correctly the first time, but if it doesn’t get it right, it can slip and mar the paper/print. It may be helpful (and reduce paper/print waste) if you help the paper feed into the printer by holding the edges and gently pushing down while the printer takes the sheet. All desktop printers have this issue, and some feed paper on their own better than others. Having a clean paper feeder will certainly help it take the paper.

You can make custom GO images to control where GO prints- and doesn’t print. For example, if you’re printing on a 13x19 sheet, but only want to coat a 11x14 area, make a 13x19 image with white in the area you want GO to print, and black in the areas you don’t want it to print. When you print this image using the regular GO printing workflow and curve, GO will only print where the white area is, and nowhere else.

I hope this helps, best regards~ Dana :slight_smile:


#6

[QUOTE=Dana-IJM;3329]I hope this helps, best regards~ Dana :)[/QUOTE]

Yes it does. Very much so. Thank you. Both those responses address my concerns. That explains why it’s happened erratically and unpredictably, and how to minimise GO waste. It also explains some of the printer feed noises I hear sometimes.

Is the black GO image documented anywhere? First I’ve seen that. Does that mean that an area of 50% grey will get 50% of the GO curve (just out of interest)?

The one unanswered question was how often is it feasible to reuse a lead sheet, if I’m not using the partly black GO image trick? How many layers of GO can I put down?

B.


#7

I’m glad the information I provided is helpful.

GO only prints in pure white image area, so the area you don’t want to print doesn’t need to be black- it just has to be anything other than pure white. I’m not certain if this is detailed in our instructions, but I have taught this to many people who come to our studio for training, and have explained to many via email how to control GO printing area.

You can make new GO curves that apply different amounts of GO using the “GO-30000” curve we supply (this is included in our Piezography manual), if you feel a paper needs more or less GO. We feel the 30000 GO curve we supply produces excellent results on most papers, but some do better with slightly more, or two coatings of 30000.

Best regards~ Dana :slight_smile:


#8

[QUOTE=Dana-IJM;3333]I’m not certain if this is detailed in our instructions, but I have taught this to many people who come to our studio for training, and have explained to many via email how to control GO printing area. [/QUOTE]

It’s a mighty long way to come to your studio, and I try to minimise the email burden on you folks. I think that both the points you made to me in reply #5 should be included in http://www.inkjetmall.com/tech/content.php?147-Piezography-Gloss-Printing-Tips and probably also in the new piezography manual, since using lead sheets and controlling the GO print area seem to be both fairly fundamental topics for gloss printing. The Tips URL was hard to stumble onto on my own, but I did read the manual carefully several times and wish I had read this - would have saved a lot of angst.

Re the “how much GO can it take” question, I didn’t explain myself clearly. Let’s say I make a print with a lead sheet and the lead sheet gets a GO coat. I reuse the lead sheet attached to my next print and it gets a second coat, and then a third. Do you have any experience about how many times I can use a lead sheet this way before it gets too many GO coats? I would reuse a lead sheet because I try not to have too many waste prints lying around to reuse like this.

Thanks again.

B


#9

p.s. OK, I’ve given the lead sheet and a black and white GO image a run and it works. Took a bit of calculus and some trial and error to get the sizing exact for what I want.

But in one run I used a clean lead sheet and I got a light black roller mark on the lead sheet. I guess the rubber print feed roller has picked up some ink from all these GO print runs without a lead sheet. I’ll need to give it a clean before I print some fresh images with ink, rather than just GO.


#10

[QUOTE=Brian_S;3336] Re the “how much GO can it take” question, I didn’t explain myself clearly. Let’s say I make a print with a lead sheet and the lead sheet gets a GO coat. I reuse the lead sheet attached to my next print and it gets a second coat, and then a third. Do you have any experience about how many times I can use a lead sheet this way before it gets too many GO coats? I would reuse a lead sheet because I try not to have too many waste prints lying around to reuse like this. B[/QUOTE]

We will relaunch InkjetMall in May with a lot of videos, etc… and we will also be updating the manual. We will cover more and more visually soon.

If you use a lead sheet to try and bleed coat the GO (print past the border) then you may want to use fresh lead sheets every few times. But, you can also create a page set up that encompasses the entire size (with the bleed sheet),but make a white rectangle on a larger black canvas to precisely put the GO where you want it and not waste printing GO or print GO on the lead sheet if you do not want it.


#11

[QUOTE=jon;3345]But, you can also create a page set up that encompasses the entire size (with the bleed sheet),but make a white rectangle on a larger black canvas to precisely put the GO where you want it and not waste printing GO or print GO on the lead sheet if you do not want it.[/QUOTE]

Thanks, yes, I worked that out, and my reference to calculus was to the slightly tricky calculations to get this spot on, since I needed to calculate the non-print border area very precisely with some trial and error. It’s a pity that QTRGui only has one custom page size, and can’t store several as far as I can see.

I assume that a lead sheet would also enable me to print closer to the leading edge, rather than leave a 1" border to deal with the limitations of the dithering algorithm.

Thanks very much for the support. Appreciated as always.


#12

Perfectly clear!

I had started to use the rear manual sheet feeder which avoids the grabber marks but can be a bit “onery” to use.

It is interesting to add that I have found that matt(e) paper is much less likely to show the grab marks.

Dana, on another subject:

Can you explain exactly why there is the whitish “discoloration” on the edges of the paper when one uses an insufficient margin?

Elliot


#13

Yes, the grab marks are more of a problem on glossy papers.

Are you referring to the micro-banding within the top and bottom 1" of paper? This is only an issue with desktop printer models, and is related to paper feed at the very top and bottom of the sheet.
If this isn’t what you’re asking about, can you possibly attach a photo showing this “discoloration”?

Warmly~ Dana :slight_smile:


#14

Hi Dana:

I allude to the whitish area on the sides of the print if one does not leave a margin that you noted should be one inch. I have experimented; it is possible to leave a smaller margin and NOT have the microbanding, i.e., the whitish
areas at the left and right margins of the print. Leaving the one inch margins means that with the smaller paper sheets the size of the print is necessarily truncated. For example with the 8 1/2 x 11 inch paper the image size is significantly compromised to about 6 1/2 inches by 9 inches. As far as I know, the need to leave the more generous margin is NOT necessary when using K3 inks. I believe that I mentioned the whitish areas to you previously Dana.


#15

Incidentally, why wouldn’t one elect to use the manual rear sheet feeder rather than use the “feeder sheet” solution Dana?

An important question: [B][UDo you know if] the microbanding occurs if one uses the manual rear sheet feeder rather than the front sheet feeder?[/U][/B] If not, then one can indeed “use” a significantly larger area of any given paper size. For example, one “recover"s” the use of 1 inch on all image sides of the 8 1/2 x 11 sheet of paper.


#16

Hi Elliot~

In my experience with many different Epson desktop printer models, the micro-banding at the leading and tail end of the paper when printing with Piezography occurs within the top and bottom 1", but is worse within about 1/2" from the paper edge. Different printer models have different paper feed options, and some work better/differently than others. If your printer is fussy about feeding paper in the top auto feed slot, and you feel your results are better (and paper feed is easier) using the front or rear manual feed paths, then certainly print that way. Our specific R2880 printer doesn’t feed paper well/consistently with the front or rear paths, so we mainly use the top feed slot- but as the printer manual says, the manual paper feed slots are recommended for heavy weight papers. QTR controls printers differently than the standard Epson drivers, though a warning does pop up when you select “borderless” in the Epson print driver, to let you know the print quality at the top and bottom of the page will not be the best.

Happy printing~ Dana


#17

[QUOTE=Elliot;3571]I had started to use the rear manual sheet feeder which avoids the grabber marks but can be a bit “onery” to use.[/QUOTE]

[QUOTE=Elliot;3576]Incidentally, why wouldn’t one elect to use the manual rear sheet feeder rather than use the “feeder sheet” solution Dana?[/QUOTE]

Somehow I missed this last year. It falls into the general category of “things I just discovered but should have discovered years ago”. I have some issues with the regular multi-sheet feeder grabbing the lead sheet cleanly, and only just realised (i.e. pointed out by another user) that there’s a single sheet feeder, which was still in the wrapper in the box and long forgotten. We will see just how “onery” it is.

Question: using this single sheet feeder option on my R1900, there won’t be any paper feed roller marks, will there? So for the GO overcoat, I could dispense with the lead sheet, couldn’t I?

[QUOTE=Dana-IJM;3572]Are you referring to the micro-banding within the top and bottom 1" of paper? This is only an issue with desktop printer models, and is related to paper feed at the very top and bottom of the sheet. [/QUOTE]

Eh? this is also news to me. Why is this? What constitutes a “desktop printer” for these purposes? Based on another thread today, I assume an R3000 is a desktop printer, since it displays this micro-banding, but based on information from another user I suspect that a 3880 isn’t, as I’ve been told that it doesn’t. Odd, as I thought that they were rather similar.