What is an expression for finishing up work on a newspaper/magazine issue?

Do want to sound like a professional?

put the paper to bed

..is the time-honored phrase in use since at least the turn of the previous century.

When the paper heads to press and newsroom has signed off all pages.

That said, and paraphrasing...

"Today we are putting the (February) issue to bed."

...sounds better. A professional would understand that there is a deadline.

I can personally attest that this is the journalistic jargon. I worked at a major up-state NY Daily tabloid in distribution, editorial, and graphics in the US during the 1970s-1980s; we printed in-house the morning edition.

We had a soft-8 hard-10 p.m. deadline for turning in composited stories. There was a little more leeway for graphics and cutlines.

However, I also did some work on weeklies and monthlies, and those we sent out to local printers capable of handling tabloid..

The publishers of those were often ignorant as to the real terminology. It was quite some work to introduce jargon to people like that.

If they do not understand that, just say

We are wrapping it up i.e. "It's a wrap".

Younger people seem to get the cine jargon better...