Photo on Aluminum with "Bars"

[Joe Pelonio]

The customer provided the artwork and they might not have caught my instructions to scan the picture horizontally since I had engrave it
that way to fit the material in the laser. Is that the cause of the
vertical "bars" or has someone seen something else do this?

http://members.aol.com/bisjoe/graphic2.jpg

[Dave Jones]

Curiously, those bars exactly match the spacing between the letters in the top part.

[Joe Pelonio]

You're right, I hadn't noticed that.

[Dave Jones]

When you engraved it was it facing in the direction shown in your photo, or was it engraved sideways so that the text was on the side instead of on the top?

In other words, were those stripes vertical or horizontal when the plate was engraved?

If the plate was rotated and those stripes were horizontal when engraved, then maybe it has to do with the engraver moving a shorter distance in the X axis when it got to those spaces. If that's the case you might be able to add a line outside of the plate (which could engrave on a scrap of wood or metal next to the plate). That would force the laser to keep a uniform width on the X axis.

On the other hand, if the plate wasn't rotated, then I don't know what happened. (I'm assuming your laser is like mine and "scans" quickly back and forth on the X axis while slowly moving in the Y axis)

[Frank Corker]

Hi Joe,

Same thing happened with me doing stuff side on. Only happened the once and I hope never again. Usually I do the writing seperate to the picture, also cuts the time of the work down.

Photograv sometimes does that also if you digitise it and then when you put it in Corel flip it onto it's side. They are quite stringent on that in their instructions.

[Joe Pelonio]

Thanks guys.

Dave,

The material is 12"x16" portrait, so I had to engrave sideways. The file was a pdf with the photo and lettering all set up actual size by the customer. Frank, next time I'll block the lettering with white outline-less
boxes, run the photo, then block the photo and run the text. That
solves other issues as well, because the lettering will be bolder if
I run it at a higher power than the photo, especially if my customer can't get a better anodizing job.