Joining a head modelled in 'mirror' mode?

I am modelling a head using mirroring so one adjustment on one side affects the other. This creates a line down the centre which I know is because of subsurfing. My questions are:

1 How do I join the two parts of the head into one mesh and if I do, is it hard to get back to editing one side as a mirror of the other?

or can I …

2 Just merge the vertexes right down the centre, eradicating the ‘ridge’ that you normally have but still be able to model symmetrically?

I know these sound like the same question but the first seems permanent but the second would at least allow me to remove the hair-lip effect I have but still continue modelling/tweaking the mesh…

As far as I know of that’s not possible.
When you join two sides in one mesh and joing the vertices you’ll get rid of the line but you’ll also lose your mirror.

Don’t think about the line as long as your modelling.
Join meshes at the end when you’re satisfied.

You can join both sides - Select both sides then press Ctrl-J

After they are joined select all the seam vertices and then remove doubles.( In edit mode W key).

If your two havles are aligned perfectly, your seam will be welded together.

Here’s an explanation I did awhile back

As to mirroring again, just delete one half of your mesh and make a new copy using Alt D and Ctrl M

vliegtuig, thanks - I can model without but thanks for answering q 2 and Room335 - thanks because that easy enough to do for a quick test render.

umm…you know that the mirror modifier does all this and automatically removes the seam for you, right?

well, as long as the mirror modifier is first in the modifier stack.

Then all you have to do is hit ‘apply’ when you are happy with the results.

[email protected], Thanks! I didn’t realize that. It Works great!

Is this modifier new in 2.40? How good does this application get!!

It is very satisfying knowing that the developers are users and implement features to improve everyones experiences with blender!