Paper Thickness

[HowardG]

I was hoping someone might be able to help me understand the Paper Thickness setting in the Epson driver for the 7900.  My understanding is that when using Epson media this can be ignored as when choosing the Epson media from the driver or printer panel the paper thickness setting and the platen gap will be set automatically and these will read 0 in the driver.

But what about when using third party papers?  I assume that when choosing the Epson media setting from the driver that is recommended with a particular icc profile that the driver then sets the correct paper thickness (while still calling the setting a '0' as it is neutral for that particular chosen media) for that particular Epson media.  What then to do with the Paper Thickness settings for third party papers?  Should one leave the setting at 0 for all papers unless they are experiencing head strikes or smudges and thereby leave well enough alone?  Should one use the manufacturer reported paper thicknesses to do anything in the absence of such problems?  What about the platen gap...is there a certain paper thickness above which the platen gap should be increased above standard?  Is the purpose of the Paper Thickness setting only to automatically change the platen gap, or does it do something else as well?  Has anyone found a need to change the suction above standard for any thick papers? Yikes, lots of questions....so thanks in advance

Howard

[howardm]

I can only relate my 3800 experience and that is that most any thicker, non-RC type paper will require Wider lest I get a headstrike. I don't
see any diffference between Normal and Wider

[HowardG]

I can only relate my 3800 experience and that is that most any thicker, non-RC type paper will require Wider lest I get a headstrike. I don't
see any diffference between Normal and Wider

Howard,

Do you just adjust the platen gap or also the paper thickness setting in the driver?

Howard

[howardm]

depends on my mood

almost always Wider unless there's a reason not too.  Mr. Chan indicated that there was no qual. differnce between Normal & Wider so
why not?

Then depending on specific paper, thickness will vary from 3 (RC) to 5 or even 6 for the heavy FA sorts of paper

[HowardG]

depends on my mood

almost always Wider unless there's a reason not too.  Mr. Chan indicated that there was no qual. differnce between Normal & Wider so
why not?

Then depending on specific paper, thickness will vary from 3 (RC) to 5 or even 6 for the heavy FA sorts of paper

Is the paper thickness used by the driver to do something other than adjust the platen gap?  Do you always adjust the paper thickness to represent the manufacturer's stated thickness....and would any input into this field be the third party thickness above and beyond the thickness of the Epson media you chose in the driver?

[larryg]

on the 7600  I always manually (on the printer menu itself) changed the gap to wider for Canvas and other thicker materials.  I believe it also has something to do with the cutters settings also?

[howardm]

Is the paper thickness used by the driver to do something other than adjust the platen gap?  Do you always adjust the paper thickness to represent the manufacturer's stated thickness....and would any input into this field be the third party thickness above and beyond the thickness of the Epson media you chose in the driver?

I honestly don't know how the thickness setting interacts w/ the gap setting; whether one overrides the other or there is some combining.  You get a sense of what thickness setting to use (3 for regular paper, 4 for slightly thicker, 5 (maybe 6) for a lot of  fine art that is quite thick.

[AaronPhotog]

Actually, the way it works is that "Thickness" refers to the actual paper thickness in .10mm.  Then, the platen gap refers to the clearance above that.  I don't know what the actual clearances are, numerically.

For example, I just measured the thickness of a sheet of Harman Gloss FB Al with a stainless steel caliper.  It measures .32mm.  So, a Thickness setting of 4 should be enough for this paper.  I've typically used 5 just to compensate for some expected curling and a little swelling (I also spray the back of large fiber based glossy sheets with water and let them partially dry to counter the tendency to curl when ink hits the front surface).

Mr. Chan's web site recommends a setting of "Wide," not "Wider" for the platen gap (the space from the surface of the paper to the platen).  So, I use that, too.  With this paper, which is very good at holding detail, the results look fine to me.

The combination of the settings and spraying the backs of large sheets completely eliminates scratches on the surface of the Harman FB Gloss papers and similar fiber-based glossy papers as well.  

The paper should be stored face-down to help it lay flat when it comes out of the box.  Always pull the sheet that would be the bottom sheet if it were right-side-up (now the top sheet) first.  The edge may drag on the back of the sheet below, but it won't scratch either the face of the sheet you are pulling out, or the back of the sheet below, even if the edge slides away on the back.  If you do the opposite, the back of the sheet can scratch the glossy surface of the sheet below it, even if you think you are being careful to lift it up.

In case you missed my posts about this in the thread about scratches on Gold Fiber Silk:

The method for spraying is simple.  Place the print face down on a clean surface, such as clean foam-core.  Use a fine mist sprayer to cover the back with a fine spray of clean (you can use distilled) water.  Smooth the water to make it even all over the surface with a folded soft paper towel.  The print paper will curl toward the back at the edges and take on an "M" shape, about an inch or two high at the high points.  This is the opposite of the way it wants to curl in the machine when ink hits the surface.  This is a good time to set up or check your print parameters.  Wait for the paper to dry so that the edges are up about an eighth of an inch (about 3mm) and you can still feel a coolness on the back from evaporation.

Then, with the 3800, load it in the sheet feeder flat and straight as possible at the back of the feeder.  Push the paper advance button.  That will cause the machine to grab the paper and pull it into the machine to the starting position (don't wait and let the printer grab it after you've hit the "print" button).  This way it takes on the slight forward curl it needs to feed smoothly.

Push print.  When the paper starts to come out of the machine, but before it has quite reached the face of the printer, reach under the leading edge and just barely support the front with the tips of your fingers until the leading edge of the paper is just past the first joint in the receiving tray.  At this point, the front of the paper will want to touch down anyway, and you can take your hand away and let it feed on its own from there.

That's it.  You'll have beautiful scratch-free prints.

Aloha,
Aaron

[howardm]

Thank you very much Aaron.  I have some curled edge Innova paper that I'll give that a spray method a go.

[AaronPhotog]

Thank you very much Aaron.  I have some curled edge Innova paper that I'll give that a spray method a go.

Before you do that, the paper should be flat.  I'm assuming that it is curled up at the edges.  Just store it upside down for a while and it should flatten out.  If not, before you spray it, lay it upside down (as in the above post) on the smooth surface and bend it up slightly on one side while holding the other side down and lightly rubbing along it to take out the curl.  Then, do the same to the other side.  Be careful not to over-do it and cause a kink or a mottled surface.  Once it's good and flat, then spray it and let it sit as above so as to counter the tendency to curl inside the printer.

Good luck.  Let us know how it works.

Aloha,
Aaron

[HowardG]

Before you do that, the paper should be flat.  I'm assuming that it is curled up at the edges.  Just store it upside down for a while and it should flatten out.  If not, before you spray it, lay it upside down (as in the above post) on the smooth surface and bend it up slightly on one side while holding the other side down and lightly rubbing along it to take out the curl.  Then, do the same to the other side.  Be careful not to over-do it and cause a kink or a mottled surface.  Once it's good and flat, then spray it and let it sit as above so as to counter the tendency to curl inside the printer.

Good luck.  Let us know how it works.

Aloha,
Aaron

Aaron, thanks very much for the input as help is appreciated.  My printer is a 7900, so the paper should be adequately held down by the suction (I would think).  I also have some concern, given the suction, in trying to wet the paper and then exposing it to suction....would this be a problem in introducing moisture into the machine?  

As it turns out, when I asked the question about the paper and platen settings it was more of an issue of my just wondering about them as when printing in color I had no problem leaving the settings at whatever was chosen automatically by the printer when I picked the media type dictated by the icc profile for the fine art non-Epson papers.

Now, though, I do have a problem.  I started trying B&W printing for the first time last night and am finding scratches and scuffing on multiple media.  I think this turns into a whole new topic, so I am starting a new thread for it....please have a look as any further help or ideas would be appreciated.  The new topic is here:

http://luminous-landscape.com/forum/index....showtopic=33813

Howard

[howardm]

Aaron,

how wet do you get the back and how long do you let it sit/evaporate?  I'm assuming 'evenly damp' and a couple of minutes
but just want to verify

[AaronPhotog]

Aaron,

how wet do you get the back and how long do you let it sit/evaporate?  I'm assuming 'evenly damp' and a couple of minutes
but just want to verify

Howardm,

Not too wet.  I just use a little fine mist hand pump sprayer, nothing fancy.  It's one you can get from most drug stores that just fits in one hand.  The bottle part is about 3" high by 1" in diameter, and the top has a small fine hole in the side of the pump head.  You just push it down and squirt, squirt, squirt from a foot or two away until the whole sheet has little tiny droplets all over the back, but not too much.  I don't want it really soaked or to have water running off.  Then, I just use a piece of paper towel, folded in quarters and kind of use it like a very loose squeegee to even out the droplets in both directions and soak up any excess so the back of the print paper is evenly wet and there are no blank spots

Here in Hawaii the humidity is usually in the mid-fifties, but it only takes a few minutes for the paper to settle back down enough to load.  I'd say about five minutes or less, but I haven't timed it.  I usually go ahead and check all my printer settings while the paper is drying and settling back down.  By the time I've finished checking all the selections, the paper is usually just about ready to load.  It will be almost flat, but still cool to the touch from the ongoing evaporation.

Aloha,
Aaron