do I need to eliminate overlapping objects for printing? - illustrator

[Carolina Solis]

I'm doing designs for Red Bubble and  I saw a video which this person makes "clean" designs for Red Bubble, not having one shape under the other. Does this affect the printing process?

[Monika Gause]

While this might be necessary for cutting, it won't affect printing, since objects knock out the background by default.

And since most probably you upload JPEGs and PNGs for printing at Redbubble, it doesn't make any sense whatsoever.

[Carolina Solis]

Jajaja that last sentence is funny because for new people in Photoshop and illustrator, nothing if this programs make sense. They make it so complicated! Even exporting a file in a specific size, I couldn't do it. Now I know I have to use 72 ppi and the size I want so it doesn't change. 

Thank you for your help!

[Monika Gause]

"for new people in Photoshop and illustrator, nothing if this programs make sense. They make it so complicated!"

They make it so that professionals can do their job. The application won't release the burden of learning the tools, basics, techniques of the trade.

And someone who doesn't understand the trade shouldn't produce a tutorial about it.

[Jeff Witchel, ACI]

You don't have to worry about overlaps and deleting what's in back. If you can't see it, it will not print. 

Can we see a link to this video you mentioned?

[Carolina Solis]

Thank you for your answer. The video explanation it was my mistake, she did this just in some parts but not in all the design. Thanks again!

[Braelen]

Though objects you don't 'see' arent printed digitally, they will be printed if they're plated for a press. Trust me: watermarks on a standard layer, even when unchecked, is still data that'll be interpretted on the plate maker. So either just delete it to be safe or place things like watermarks on a template layer that's checked to be visible but not printed.

Hope this helps.