Major difference in Offset Vs Flexo Prepress

[shorty83]

I currently run the prepress department at a narrow web label and packaging company. I have been asked to go to a sister company to train their prepress department to recognize when art needs to be adjusted to print well. The problem is that all I know is flexo labels and packaging & our sister company is an offset shop. Are there major differences in offset vs flexo prepress besides trapping and no distortion for plates? I have also heard that offset can't lay down ink dense enough so they like to keep as much in 4cp as possible even if there is small reverse text in that area. I think its a bit weird to have to go "train" prepress people at a company with a completely different form of printing.

 

[Tim-Ellis]

Hello Shorty83,

I manage a prepress department handling flexo, offset and digital. You'll be just fine.

Yes you won't have to worry about Distortion for plates and cylinder depths. Yes, you might have to get to grips with the gripper bar.

Trapping requirements will depend on their equipment.

My advice is just watch what they do and ask questions about how and why they are doing it. In time you'll see the better ways to work based upon your experience. Be honest, don't say your an expert, don't risk being found out, just tell them your here to help them where you can.

 

[Stephen Marsh]

I would say that yes, there are “major" differences in prepping work for litho vs. flexo. Using standard “LAMs” plates for example, flexo prepress is used to having to create separate line and tone plates, however with current NX/HD flexo systems, only one plate may be required. Litho does not have to concern itself with minimum dots, bump curves etc. Perhaps you could use the FIRST design guide as a start point for your training topics:

http://flexography.org/wp-content/up...sign-Guide.pdf

EDIT: You can sign-up for the latest free PDF version 5 here:

http://flexography.org/first-5-0-design-guide/


Stephen Marsh

 

[chordchaser]

Hi Shorty,

I ran an offset dept for years and for a few years took over a flexo dept.

The following is based on my experience, so for what it's worth:

First, if you are open to it you will learn a ton and it will help you to become better in both areas. It increases your value, look at it that way.

Second, you're going to learn that flexo has limitations that offset does not. This all depends on the hardware and software both in prepress and in production, of course, but that's generally true. Reverse type in spot color is not a problem at all, in fact if you have the right equipment 4color reverses are not near the problem they present in flexo.

Imposition is likely where your struggles will be and you might want to find out what software they're using.

Hope that helps.

Neal

 

[shorty83]

Thanks for the info everyone. I am actually kind of excited to learn about offset. Flexo is starting to get boring