Question about paper thickness / Platten gap

[huguito]

I use an Epson 9600,mostly printing on Baryta papers, Fine art papers like Epson Hot Press and Canvas.

In the control panel on the printer itself a setting can be chosen for Platten Gap, I use it mostly on Standard.

Once I order a print from Photohop, in the menu showing all the different settings, there is one that shows paper thickness, in 0.1's of a millimeter.

I assume that platten gap controls the distance between the print head and the suction platten.
I also assume that thickness controls the distance between the 2 traction rolls that move the paper.

Questions:

I am wright in those assumptions?     
Is there a relation between those two settings that I miss and could reflect in print quality? 
Is that a case where one of the two settings overwrite the other one?

Thanks for your help

Hugo

[hugowolf]

You are correct in your assumptions, and one cannot override the other. But I don't know if the platen gap setting is absolute or relative to the paper thickness setting. I assume the platen gap setting is relative when it is set to auto.

Brian A

[huguito]

In my printer panel, on the printer itself, I don't have the option of Auto, the availabe options are;
Thin, Standard, Wide and Wider

In the Epson driver menu, the paper thickness default start point is always 0.1 mm and this doesn't change with changes to the platten gap

Since I start noticing this setting, I just measure the media thickness and enter a value on that window, just one more step.

Hugo

[Wayne Fox]

I also assume that thickness controls the distance between the 2 traction rolls that move the paper.

I think this is correct ... basically how much space is being allowed for the media through the transport system.

I assume that platten gap controls the distance between the print head and the suction platen.

I think the platen gap is relative to the paper thickness, not the suction platen.  As you increase the paper thickness the platen moves with it.  So the wider/widest settings are relative to the paper.  Basically it sets the distance allowed from the top of the paper to the print head platen.

Some of my customers using 3rd party papers with scratching problems have tried to resolve this with a wider platen gap setting, when in fact they were using an epson premium luster preset and the problem was the paper thickness.

[Manoli]

Some of my customers using 3rd party papers with scratching problems have tried to resolve this with a wider platen gap setting,

As I do ..

when in fact they were using an epson premium luster preset and the problem was the paper thickness.

Could you clarify your post - why was the paper thickness a problem when using an epson luster preset -
and what's the solution for the head strikes/scratching problem, on a given paper, other than increasing the platen gap setting to Wide or Wider ?

[JRSmit]

As I do ..

Could you clarify your post - why was the paper thickness a problem when using an epson luster preset -
and what's the solution for the head strikes/scratching problem, on a given paper, other than increasing the platen gap setting to Wide or Wider ?

The epson driver has an option to determine the paperthickness, at least on the 4900 and the 9900.
I use that to set the paperthickness. And the platen height to auto.
The platen is relative to the paperthickness.

[Manoli]

The epson driver has an option to determine the paperthickness, at least on the 4900 and the 9900.
I use that to set the paperthickness. And the platen height to auto.
The platen is relative to the paperthickness.

Thanks the reply. I'm still using the 3800 which has an option to set the paper thickness (but not one to determine it - as far as I can see).

So when using the Epson Luster paper preset - (a) either measure the thickness of the paper you're using to print on or (b) set it in relation to the thickness of Epson Luster itself ( i.e. wide, wider etc). Is the paper thickness set in each individual Epson profile or is it hard baked into the printer itself ?

[howardm]

get one of these and get the real answer.  many paper vendors tell you the thickness in mils or mm on their website too.

http://www.amazon.com/Neiko-01407A-Extra-Large-SAE-Metric-Conversion/dp/B000GSLKIW/ref=sr_1_1?ie=UTF8&qid=1410863604&sr=8-1&keywords=dial+caliper

The paper thickness is not coded into the icc profile but one of the supplemental files that is included in the driver installation.  Most/avg lustre RC papers should be set to '3'

[JRSmit]

Thanks the reply. I'm still using the 3800 which has an option to set the paper thickness (but not one to determine it - as far as I can see).

So when using the Epson Luster paper preset - (a) either measure the thickness of the paper you're using to print on or (b) set it in relation to the thickness of Epson Luster itself ( i.e. wide, wider etc). Is the paper thickness set in each individual Epson profile or is it hard baked into the printer itself ?

My experience  :  add 0.1 or 0.2mm to the vendor specified thickness . So if vendor says 0.3mm i would go for a paper thickness setting of 0.4mm at least.

[huguito]

That's the same tool I use before entering a thickness value on the Epson Driver.

[Wayne Fox]

As I do ..

Could you clarify your post - why was the paper thickness a problem when using an epson luster preset -

because the paper they were using was thicker than EPL.  Not only did it make it more difficult to load, but also didn’t allow enough room for the paper to pass through appropriately.  

Quite a few third party papers, especially the ones for PK inks, build their profiles using the EPL paper setup, which sets the ink load.  they will often tell you to use a wider platen gap, but many of these papers you may also need to add a small amount to the paper thickness as well.  Even some epson papers such as exhibition fiber or the canvas may benefit from adding .1 mm to the thickness

If you increase the paper thickness, this widens the transport system. Since the paper is being sucked against the back of that system, a wider paper setting means the print head and  platen are further from the surface of the paper - the space created by the increase in the transport gap is on the top side of the paper.  If you increase the platen gap, this also moves the platen away from the transport system and increases the distance from the paper.  However, the ideal distance is achieved by not having to increase the platen gap if you can help it.  As you increase the gap there will be slight changes and possible degradation of the image.  This is usually very subtle and hard to see, and often only detectable on high quality gloss type of papers. Again this is extremely minor,  and is certainly better than head strikes and scratches.

Basically what I always recommend is to find out exactly how think the paper is you are using, and setting the thickness accordingly or even slightly higher.  Then if you are getting head strikes or micro scratches, try increasing the platen gap.  Other things that can exacerbate micro scratches from the transport system is stiff or curled paper.  Printing with 45% humidity or higher helps with this.  Another thing that I’ve seen help with these small scratches is slowing the printing down ... add a slight pause between each pass for “drying”.

[JRSmit]

+1 , i use the epson functionality to measure the paper thickness, and if f.i. the result indicates 2 adjacent values as ok, i use the higher one. So i round up .
Platen height is auto or normal, never had need to change that.

[hugowolf]

+1 , i use the epson functionality to measure the paper thickness, and if f.i. the result indicates 2 adjacent values as ok, i use the higher one. So i round up .
Platen height is auto or normal, never had need to change that.

What Epson function are you using to measure the paper thickness? Neither of my Epson printers seems to have this feature.

Brian A

[huguito]

Hi Jan
Can you explain what do you mean by "Using the Epson functionality" ?
Never heard that before

[JRSmit]

Hi Jan
Can you explain what do you mean by "Using the Epson functionality" ?
Never heard that before

In the menu on the printer where you can define your custom papers, there is an option to determine the paperthickness, at leaat on the 4900 and 9900

[Manoli]

In the menu on the printer where you can define your custom papers, there is an option to determine the paperthickness, at leaat on the 4900 and 9900

For the Epson 3800 Stylus Pro, I downloaded this user guide from the Epson US site. Defining and measuring custom paper thickness and settings, pages 45-47 : Creating a Paper Configuration.

It's configurable via the menu on the printer, not via the driver dialog box. I haven't had the time to check this - given in good faith, but without guarantee  :~)

Thanks again to Jan and Wayne Fox.

[hugowolf]

In the menu on the printer where you can define your custom papers, there is an option to determine the paperthickness, at leaat on the 4900 and 9900

I had forgotten about that method - it is there on other Epson printers too. It is just a lot faster and easier to use vernier calipers, and it doesn't waste any paper, so I've only ever used the pattern method once to try it out.

There is a similar pattern method for head alignment.

Brian A

[JRSmit]

As an example, i am in the middle of a review on the new Hahnemuhle Fineart Baryta Satin, which according to HM has a thickness of  0.37mm. On my Epson 4900 it measures 0.5mm . I am now testing both 0.5 and 0.6 mm to see if it matters.

[rxchaos]

I came across this suggestion on a posting (I don't remember where, I just saved the needed information) for recommended platen gap settings. I use an Epson7900...

Narrow:  150gsm
Standard: 190gsm
Wide: 260gsm
Wider: 320gsm
Widest: 500gsm

[Some Guy]

For the Epson 3800 Stylus Pro, I downloaded this user guide from the Epson US site. Defining and measuring custom paper thickness and settings, pages 45-47 : Creating a Paper Configuration.

It's configurable via the menu on the printer, not via the driver dialog box. I haven't had the time to check this - given in good faith, but without guarantee  :~)

Thanks again to Jan and Wayne Fox.

I believe you still need to know the paper thickness prior.  This just nulls the overlap of the nozzles once "You have assigned a paper and its thickness" into the printer's menu.  Strictly a nozzle calibration.

Fwiw, I use some cheap $30 digital micrometer from the local "Harbor Freight" tool store and round-up since head strikes can be problematic if set too thin.

SG