Laser Tile horizontal lines

[JAIME PUJOL]

Hi All
I am new here and have a question on laser tiles. I get these horizonal lines across the whole length of a 4-1/4 tile. It starts getting better when I slow the speed. I have a 35 watt Epilog TT laser and purchased the Epilog alignment and alignd the laser and it still has the lines. I hope you are able to see it in the photo. I used CorelDraw X4 Photo at 300 dpi (not using PhotoGRAV) and the machine setting is 30S/100P 300 dpi.

Thanks for any help.

[Scott Shepherd]

Welcome to the forum! I can't answer your question, but I'll share my experience on an issue that looked a lot like that.

I had a photo that was a little smaller than I needed at 250 dpi. I resampled it to a different size. It looked good, however, those lines were in it. I tried and tried to get rid of it and couldn't. I went back to the photo I resized and applied a gaussian (sp?) blur to the entire thing. Very small, only a couple of pixels. Engraved it again, the lines were gone.

[Ross Moshinsky]

Hi All
I am new here and have a question on laser tiles. I get these horizonal lines across the whole length of a 4-1/4 tile. It starts getting better when I slow the speed. I have a 35 watt Epilog TT laser and purchased the Epilog alignment and alignd the laser and it still has the lines. I hope you are able to see it in the photo. I used CorelDraw X4 Photo at 300 dpi (not using PhotoGRAV) and the machine setting is 30S/100P 300 dpi.

Thanks for any help.

Engrave at a higher resolution. I'd suggest 500dpi or greater. Expect engraving time to double as a result.

IMO, all laser engraving should be done at 500dpi or better. Anything less does not look good.

[Martin Boekers]

Try rotating the image and re-laser it see if the lines change direction.

That will tell you if it is the file or somethings else.

Sometimes I have to narrow things down a piece at a time.


Marty

[Dan Hintz]

Jaime,

Was the dithering done by the laser driver or was it done by a different piece of software before sending it to the laser? If a different piece, did you change the images size after dithering?

[AL Ursich]

Any chance you changed the image size after ruining it through Photograv?

I have seen that posted a few times over the 5 years I have been reading the Forums.

You can't change the size after Photograv.

AL:D

[Scott Shepherd]

Al, he said he didn't use PhotoGrav.

[JAIME PUJOL]

Wow! Thanks for the quick respon. I think need to look in my procedure in resizing a photo before engraving. I will try your suggestion
applied a gaussian ( Not familiar with this process)
rotating the image (Great idea)
Not sure what is dithering, I Create the layout and set the speed, power and send direct to Epilog machine using there drivers.

Thanks so much will work on it and get back to you.

[Sandy Henry]

Same problem with my Epilog TT 45 watt. Photos on tile almost always had horiz. banding. Now have Epilog Legend 60 watt. Have the same type of banding when engraving micro-surfaced acrylic (Romark). Epilog tech, Ian, wants me to send photo of my test shots & he will trouble-shoot with me. I'll let you know if we have any success...don't hold your breath!

[Ken Liversidge]

That looks like you have your image at the wrong resolution. Any chance you resized or cropped the image without resampling?

I used to have similar problems, but diagonal banding, with my Accuris. I was told that if I removed all other printer drivers from my computer the banding would go away.......surprisingly enough, it solved the problem...

[Ross Moshinsky]

That looks like you have your image at the wrong resolution. Any chance you resized or cropped the image without resampling?

I used to have similar problems, but diagonal banding, with my Accuris. I was told that if I removed all other printer drivers from my computer the banding would go away.......surprisingly enough, it solved the problem...

That is definitely a resolution issue. Try engraving at a higher resolution. 300dpi is VERY high for an image on a computer. 300dpi is VERY low for printing. I don't do a lot of photos, so going to 500dpi or better might result in weird half tone results, but I've done a lot of testing with other images and 500dpi is my favorite resolution. It looks as good as 1000dpi but takes half the time. I run 90% of my stuff at 500dpi. Any time I go lower, I'm always disappointed.

[Frank Corker]

That might also be caused by a dirty encoder strip. Have you tried moving the physical location of the tile on laser bed? Such as 6 inches down 6incches right using same image.

[JAIME PUJOL]

This is great stuff. In CorelDRAW is resolution and resampling the same? This could help I first.
#1 Cropped Image
#2 Resample to 300 resolution if needed
#3 Powerclip into a square and center
#4 Print 30 S/100 P 300 resolution
I always try to keep the photo and print resolution the smae is that right?Will try at a higher resolution and keep you posted.
Thank so much

[JAIME PUJOL]

Dose anyone know how to crop a photo in CorelDraw to a size. So I don't have powerclip.

Thanks

[Ross Moshinsky]

This is great stuff. In CorelDRAW is resolution and resampling the same? This could help I first.
#1 Cropped Image
#2 Resample to 300 resolution if needed
#3 Powerclip into a square and center
#4 Print 30 S/100 P 300 resolution
I always try to keep the photo and print resolution the smae is that right?Will try at a higher resolution and keep you posted.
Thank so much

Screen resolution and print resolution are two completely different things. http://www.luminous-landscape.com/tutorials/understanding-series/und_resolution.shtml When I'm engraving, I'm far less concerned with the screen resolution and far more concerned with the printer resolution.

[donald bugansky]

I think it's more of a resolution issues as it appears to be more of an moire effect.

Bugs

[JAIME PUJOL]

Thanks Ross that website help me understand more on resolution. I did couple of test run today. With some improvements I believe the problem is along what everyone stated in regards to resolution. Today test run. Here is my procedure.
1) Import photo and resize using resample
2) Crop to fit my work area
3) Resample to 300 DPI ( Photo is at 72 dpi in order to process to laser need to make higher dpi)
4) I try 300,400 and 600 dpi on machine output. all about the same result with the lines. Put better than before it could be the way I am setting up the job.
Hopefully someone will see what I may be doing wrong.
Also I never updated the driver for my laser and the machine is now six year old could this be a problem.
Thanks

[Scott Shepherd]

It's coming from the resampling. You can't just resample something that's low resolution to high resolution. It's exactly the problem I described before on the 2nd post. If you resample it, you need to apply a guassian blur to it in your photo editor.

[James Stokes]

I am in disagreement on that 500 dpi. For tile or granite I never go above 200 dpi and just normal engraving 300 dpi. That works great for me.

[Martin Boekers]

When I go to 300 dpi I get a visible "crosshatch" halftone pattern that is visible. Am I doing something wrong? When I go to 600 dpi it isn't visible.


Marty

[Linda Kroeker]

this sounds kinda like the problem I had with a photo on acrylic...a few posts down...leaving banding lines.
I've read everyones suggestions in my post and this one...but I am so computer dumb...or photo prep dumb.
Is there somewhere I can get a simple check list or something...that is from the point of scanning a photo or exporting a photo into corel.
I have looked but I just don't understand it all.
Scan, import, size it, grayscale..etc???
Linda

[Ross Moshinsky]

When I go to 300 dpi I get a visible "crosshatch" halftone pattern that is visible. Am I doing something wrong? When I go to 600 dpi it isn't visible.


Marty

No. Some people aren't as particular as others. On my materials I run daily, I've run resolution, speed, and power tests on all of them. Not once have I seen 300dpi where the letters actually looked right. They are never smooth and they are never perfectly clear. 500dpi is perfect. As good as 1000dpi as examined with a jewelery loop.

From 1 foot away, you won't notice the difference between 300 and 500dpi. 6", you will. I think my stuff should look great always, not "only from a distance".

[Norberto Coutinho]

This look me like barbed wire on original photo....:confused:

[Frank Corker]

Norbetto, that is barbed wire, I think they are actually talking about the banding marks which you can see in the background. When I first posted my reply saying dirty encoder strip, I was not able to see the picture close up on my tablet. Now that I see it closer up I would say that it has to be down to the way that the image was processed.