Oil painting on MDF, how to make the final coat non-stickyish?

[Fusion916]

So I recently finished a project with oil paint on MDF, final sanding coat was 320 grit before applying oil paint. Did a few coats of oil paint with 320 grit sanding in between. I allowed a few days of dry time in between and generally did not have any issues with the finish. I did however have issues with the final coat, even after drying for WEEKS, still being a bit "sticky". The paint is not coming off at all, it's just not silky smooth. I don't mean silkly smooth looking, I mean silky smooth to the touch.

What can I do to the final coat(s) to make the finish smooth to the touch and relatively rugged? I want to make able to put things like vases, picture frames, etc, not not have it feel "sticky"

[Jamesbil]

By "sticky" do you mean kind of non-slip? Or is it that the finish is not completely dry?
If it is dry but so glossy that it has an almost rubbery texture, you could try buffing it with a very fine grade sandpaper. 1000 or 1200 grit.
I run a cabinet workshop and if I want a matt finish I will often cut back with a fine paper like this.

[Fusion916]

Yes I mean dry but still non-slip. I guess "rubbery" texture would be the right way to describe it.

So the thing I need to do is use 1200 grit sandpaper as a last step? Can I go from 320grit -> paint -> 320 grit -> paint -> 1200 grit? Will the paint still have the gloss finish after the 1200 grit sandpaper?

By "sticky" do you mean kind of non-slip? Or is it that the finish is not completely dry?
If it is dry but so glossy that it has an almost rubbery texture, you could try buffing it with a very fine grade sandpaper. 1000 or 1200 grit.
I run a cabinet workshop and if I want a matt finish I will often cut back with a fine paper like this.

[Jamesbil]

The paper will dull it down to matt. Try a small test patch somewhere first, somewhere not seen.

[Fusion916]

The paper will dull it down to matt. Try a small test patch somewhere first, somewhere not seen.

Anyway to keep it gloss and have the non-rubbery finish?

[Whitneyville1]

The paint will eventually dry hard and glossy. Setting them in a warm sunny window or under a heat lamp will speed up the process, but it may take weeks to fully cure.

[jhollander]

For oil based it needs 30 days/ 4 weeks to get hard.