How do you use double sided *rolls* of paper?!

[Waker]

I noticed that Moab sells their excellent Entrada Rag paper in both single and double sided, including large rolls, like 44".

I'm missing something - how do you use a double sided 44" roll?
Only way I can think is to turn off cutter, proof everything on one side, when that's done, reverse roll it back and reprint other side - maybe?

Genuine question, think I might be unaware of some use for this quality.

[Ernst Dinkla]

I noticed that Moab sells their excellent Entrada Rag paper in both single and double sided, including large rolls, like 44".

I'm missing something - how do you use a double sided 44" roll?
Only way I can think is to turn off cutter, proof everything on one side, when that's done, reverse roll it back and reprint other side - maybe?

Genuine question, think I might be unaware of some use for this quality.

It is unlikely that printing the roll twice delivers correct register between front and backside. Media transport will be different due to the first printed ink layer, changed condition of the paper length itself (inner roll humidity, reversed curl, and different surface friction on the media transport axle). BTW, an exception; this may be way better on the HP Z6xxx models that measure media transport optically on the media texture, for the method: think optical mouse sensors. For the sideways register you have to consider that the print carriage sensor measures at the right side of the paper and on the reversed roll that will be the other side. To get the first print side in the horizontal center is already difficult and even more complicated on the reversed side for similar reasons as sketched above + some skew at the first print pages when the roll is not yet really running straight. Flaws in the register build up print page after print page if you choose printing both sides on the roll. Maybe there are printers that can recognize register marks at the back of the paper and compensate for that but I have not seen that in the printers usually discussed in this forum. On web offset systems that is a normal feature using stroboscopic light + optical sensors.

The way I used papers like that has been as follows:  Load the roll, let the printer cut the first leading edge, use the cutter and preferably use a landscape print page for better register and easier handling, Widest rolls are then more economic. As two sided prints usually are needed for books etc the paper fiber direction has to be considered too. Like mentioned use landscape mode that fits the pages but add about 3/4" extra at the trailing edge so after the roll print phase the sheets can be used for sheet printing (required extra depth on my HP Z3200). Though the outside roll coating is usually the better one it is wise to have the lowest density prints at that side, like text. Gives less smudges when the other side of the sheet is printed with the higher density images. Prints must be slightly more to the right horizontally than in the center.

After the roll print phase let the printed sheets uncurl/stabilise/inkdry for a day.  I use Qimage Ultimate with Corner Marks and measure the edge to first Corner Mark at the right side on the leading edge  of the printed sheets. Measure the left side like that too. Depending on the quantity of sheets I either cut the left side of the sheet that it becomes the same distance or I adjust the pages to be printed a bit. For the last measure more sheets and average the compensation.  The sheet reversed but same leading edge is inserted again (on the Z3200 I load them skewed so the printed errors to adjust sheet to blue line) and aligned to two plastic tabs put at the blue line. Head carriage sensor will measure the (cut) left side that was the right side in the first print run so that distance is set. First sheet printed and put on a lightbox to see register differences. Pin holes on the Corner Marks is another method. Tabs reset to change skew issues and possibly depth issues but the last depends on the way the printer checks that. Sideways you depend on the head carriage sensor or on changes in the printing application, the last can resolve depth register too but skew not really.

I had some mechanical tweaks on some aspects but I spare you that story.

All in all not my favorite jobs. There are good reasons to deliver two sided paper as sheets only like most distributors do, reduces some errors. But auto loading sheet inkjet printers are not that good at keeping register either and the stack of heavy papers they can handle is not that high either, 10 sheets on the Canon iPF5100 if I recall it correctly.  Flatbed inkjet printers using sheets are the best for dual sided register printing. There are roll printers in the sign world that print both sides of a vinyl/pet film roll at the same time. Either for two sided signs or for light box signs that need density for transmitted light and less density for reflected light (box light switched off). Printers for textile for similar reasons. https://www.hollanders-ps.nl/en/product/double-sided-platform/colorbooster-ds is one example.

Edit: The methods I use were for book pages mainly, small runs, Varying between A5 and A3 size, up to 30 pages. 4 to 8 pages on one print page, various paper weights. If the register is not within one mm, it is not in in register in my book, pun intended.


Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
March 2017 update, 750+ inkjet media white spectral plots

[deanwork]

Two things you can do with it. If you make a scroll that you want to hang from the ceiling and view from both sides. Or sandwich between plexi and put in a frame to be suspended from the ceiling or in a window display viewed from the street and in the gallery, have done that.

But most people just cut it down into sheets and flatten, say in a dry mount press, and use it for dual sided portfolio books. That’s what I have used it for. It’s a great value for that.

I don’t have any trouble registering in my Canon and Epson printers. I wouldn’t even attempt it with my HPs.

John

It is unlikely that printing the roll twice delivers correct register between front and backside. Media transport will be different due to the first printed ink layer, changed condition of the paper length itself (inner roll humidity, reversed curl, and different surface friction on the media transport axle). BTW, an exception; this may be way better on the HP Z6xxx models that measure media transport optically on the media texture, for the method: think optical mouse sensors. For the sideways register you have to consider that the print carriage sensor measures at the right side of the paper and on the reversed roll that will be the other side. To get the first print side in the horizontal center is already difficult and even more complicated on the reversed side for similar reasons as sketched above + some skew at the first print pages when the roll is not yet really running straight. Flaws in the register build up print page after print page if you choose printing both sides on the roll. Maybe there are printers that can recognize register marks at the back of the paper and compensate for that but I have not seen that in the printers usually discussed in this forum. On web offset systems that is a normal feature using stroboscopic light + optical sensors.

The way I used papers like that has been as follows:  Load the roll, let the printer cut the first leading edge, use the cutter and preferably use a landscape print page for better register and easier handling, Widest rolls are then more economic. As two sided prints usually are needed for books etc the paper fiber direction has to be considered too. Like mentioned use landscape mode that fits the pages but add about 3/4" extra at the trailing edge so after the roll print phase the sheets can be used for sheet printing (required extra depth on my HP Z3200). Though the outside roll coating is usually the better one it is wise to have the lowest density prints at that side, like text. Gives less smudges when the other side of the sheet is printed with the higher density images. Prints must be slightly more to the right horizontally than in the center.

After the roll print phase let the printed sheets uncurl/stabilise/inkdry for a day.  I use Qimage Ultimate with Corner Marks and measure the edge to first Corner Mark at the right side on the leading edge  of the printed sheets. Measure the left side like that too. Depending on the quantity of sheets I either cut the left side of the sheet that it becomes the same distance or I adjust the pages to be printed a bit. For the last measure more sheets and average the compensation.  The sheet reversed but same leading edge is inserted again (on the Z3200 I load them skewed so the printed errors to adjust sheet to blue line) and aligned to two plastic tabs put at the blue line. Head carriage sensor will measure the (cut) left side that was the right side in the first print run so that distance is set. First sheet printed and put on a lightbox to see register differences. Pin holes on the Corner Marks is another method. Tabs reset to change skew issues and possibly depth issues but the last depends on the way the printer checks that. Sideways you depend on the head carriage sensor or on changes in the printing application, the last can resolve depth register too but skew not really.

I had some mechanical tweaks on some aspects but I spare you that story.

All in all not my favorite jobs. There are good reasons to deliver two sided paper as sheets only like most distributors do, reduces some errors. But auto loading sheet inkjet printers are not that good at keeping register either and the stack of heavy papers they can handle is not that high either, 10 sheets on the Canon iPF5100 if I recall it correctly.  Flatbed inkjet printers using sheets are the best for dual sided register printing. There are roll printers in the sign world that print both sides of a vinyl/pet film roll at the same time. Either for two sided signs or for light box signs that need density for transmitted light and less density for reflected light (box light switched off). Printers for textile for similar reasons. https://www.hollanders-ps.nl/en/product/double-sided-platform/colorbooster-ds is one example.


Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
March 2017 update, 750+ inkjet media white spectral plots

[MHMG]

I routinely use the verso of Moab Entrada Natural 300gsm to print my personal seal and other metadata where the registration doesn't have to be perfect, just basically centered to the sheet. So, image gets printed on roll, print cut out with corresponding margins, then printed on verso as cut sheet. Some LF printers can handle large sheets easier than others. With my iPF8300 I have to trick the front lid so that it can stay open. On my HP Z3200, I just had to perfect some techniques to allow me to feed the cut sheet through the roll feed port. It's pretty easy once you get the hang of it.

Also, no matter how good one has a color managed workflow down, there will always be prints that end up as rejects for various reasons. With double sided paper, one gets to set those rejects aside and use the unprinted side for other proof prints before committing fresh paper to a new larger final print. Thus, double sided papers end up being quite cost effective compared to single sided rolls depending on how much hard proofing you like to do before committing to final print.

All that said, one huge benefit of double sided rolls has nothing to do with printing on the verso. It has to do with lay flat qualities of the finished print. The physical/mechanical symmetry of the dual sided coatings means the coating on the back side acts as a perfect anti-curl layer to counter the forward curl tendency of the image bearing coating over time. You may still have to decurl a roll of dual-sided paper inititally, but once flattened the print stays nicely flat.

cheers,
Mark
http://www.aardenburg-imaging.com