Milling your own kitchen cabinet doors? Material?

[Grop]

I just justified the purchase of a new router (OF 1400) to my wife by saying that you need 12mm bits if you're going to, for example, make your own kitchen cabinet doors. I should not have mentioned that, now I've created expectationsq(;^p... If I make my own white-painted doors, like the ones I attached a picture of, what material do I use for the panel? Is it MDF in bought doors?

 

[Ronnyh]

If it is completely smooth, it is probably mdf, if you see structure, it is likely veneered mdf.

 

[Fredrikfr]

I would like to mill a hatch that looks like this, can anyone recommend a suitable steel? My frame. Will be 8mm.