Finished interiors, which is how you get a finished bottom on an upper, is always an upgrade. Cabinet boxes are clear coated ply or melamine coated furniture board or ply as standard from most companies. Melamine is preferred as it's more moisture resistant over time. They are not ''unfinished''.

If you watch the video at the link provided, you'll see what I'm talking about the underside being "unfinished" .

I'll be sending an email to one of the Conestoga resellers and ask them about it.

Here is a link that might be useful: Unfinished bottom underside of wall cabinet

Your question is confusing.

If you are buying unfinished cabinets, then best practices is you finish the parts before assembly and then touch up post assembly. Finishing the underside is up to you.

If you buy finished cabinets that are either assembled or unassembled, the boxes are typically constructed out of sheet goods that have had the melamine applied to the one side and the other clear coated, or both sides clear coated. It comes that was AS the sheet goods, and all the manufacturer has to do is to cut to size from the cut list and then assemble, or you assemble when you receive the flat pack. All of the finishing of the box is done by another company as sheet good.

Buying cabinets that are completely unfinished and assembled is the wrong way to go about it. Your boxes get a much poorer finish that if you finish as flat goods.

I verified that the standard is that the underside of the upper cabinets are unfinished plywood even if you purchased the cabinets finished. The interiors are clear coated. There is an option to get the underside of the cabinet clear coated which runs about $10.00 for a 30" wide upper cabinet.

What happens to the bottom edges of the sides of the cabinets....maybe those come edgebanded?

ajc, I've attached a picture of the bottom of a cabinet that goodguy2k2k posted on another message that I linked below so you can see what they do to the bottom edges..

Here is a link that might be useful: Conestoga Cabinets Discussion

Standard is unfinished. $10.00 per bottom is worth it. I didn't know that was an option. Not sure if it really matters. There is really no melamine to speak in my Conestoga cabinets. Finished furniture grade plywood for boxes and hard maple painted for face frames (in my case).Very nice finishes and good quality. Not sure why you would need bottom of boxes finished unless you are worried about splashes, stains. Now you have me paranoid. I think I may tape them off an spray a clear coat of poly in the bottoms before I install.Note: The hot glue shown in my picture above was my addition. Due to the nature of the Conestoga assembly, I wanted to add bit more bottom sag protection to the Conestoga standard assembly method.The possible weak point was the front edge of the cabinet bottoms panels (and tops but they wont be carrying any weight)are slid into place and along the front edge of the panel where it meets the face frame if does not slip into a wood on wood groove - it is held in line with plastic grip tabs which are there to hold the face frame tight to the box until the glue dries. It is actually an ingenious method of allowing easy RTA assembly. This is only possible weak spot I could see in the conestoga design. So I put some hot glue on those edges underneath to shure up the joints along the bottom panel where it meets the face frame. Hopefully thins prevents any sagging that might occur if the plastic tabs don't prevent it already (they probably will, I'm just paranoid)