Identifying A 3c Wf 10x10 That Seems To Be Offset Printed

Can anyone help me work out what this stamp is, please?
It is clearly 10x10 and doesn't seem to have been re-perfed (very wide borders).
But the color made me wonder, so I did the foil test and it does not raise an oval.
So that makes it Offset, right? Except that as far as I know, Offsets are p.11x11 only.
Thanks in advance.

This is not an offset, it's an engraved stamp. Run a fingertip very lightly over the surface, you will feel the raised ink.

Be sure to clean your fingertip first and don't wear gloves.

Thanks, guys. I am a bit confused right now. The "foil" test used to be infallible for me, but this week ... I dunno, ... I'm getting things like this 3c that won't show an oval although there must be one ... and even where I do see the ovals, they are soooo faint. I tried a new piece of foil! And cleaning my fingers more thoroughly! Unfortunately, the gentle stroke to feel the raised ink has never worked for me. Hey ho.

If you place it next to a 3 cent offset stamp, it will be obvious that it is engraved and not another offset.

In my opinion, once you've looked at enough W/Fs in hand you'll more easily be able to see the difference between the three types of printings. Sometime flat plate and rotary bare some resemblance but the off-sets just have the look to them that's more recognizable as different from the other printing methods.

Looking at them together will help in that regard.

Unfortunately, 20 years of studying WFs hasn't brought me to a position of trusting my eyes without confirmation.
Thanks for all the advice.