Problematic leaves on my paphs...
 

The first picture (starting with the one on top left, going to the right, then from bottom left to the right) shows the pleating I have never seen before. They run along the length of the leaf and I now see this kind of look a lot when I go to orchid stores. I hope they are nothing serious to worry about.

The leaf in the first two pictures also shows small areas of indentation. This I see a lot. While most leaves on my paphs are perfectly fine, some have one and others have quite a few of these on them.

I noticed that the little brown spots are the results of physical damage, like a bruise. Most of my paphs are sitting next to my bed, so sometimes some of the leaves get smacked by the bed cover. The leaves that get hit and bent seriously would develop these brown bruise in a few days later. However, I also noticed that some brown spots just happen without being physically damaged, like on the newest growth on a paph that's sitting in the kitchen (where it doesn't get smacked haha) I see these little brown spots on one of the flower as well. No, I didn't smack the flower.

What really bother me the most of all this are the manifestations seen in the last three pictures. The collection of little black dots toward the end of the leaf seem to be lodged inside the leaf as the leaf surface is perfectly smooth. The underside of that leaf has the same look.
The deformed leaf in the last picture along with some dark indented area is also something mysterious to me.

None of these are spreading by the way.

Not saying that you have the same outcome but I noticed - late ! - that my phal and paph leaves were being damaged when I started using a 2gallon watering can to drench my orchids. I had them in the bath and was drenching them from above. Well - I stopped doing that. Now I use a smaller vessel that I fill from the 2 gallon.

Hi NYCorchidman, I was having similar issues with my mottled leaf paphs and also seeing a yellowing of the leaves over a period of time. When I knocked them out of the pots, the roots were pretty poor. They seemed to be somewhat rotted. I changed the mix to a CHC mixture which allowed the mix to dry out quicker. I do have to water a little more frequently but the plants seem to be doing much better.
I also cut back on fertilizer because it tends to build up more with CHC.

Bill

I know paphs don't like their leaves misted or wet in any way, could it be so with yours? Checking roots is always a good idea though.

Bill- Yellowing of leaves can be just a natural aging process. My Maudiae types tend to keep their leaves for over two years before turning yellow and drop. My fairrieanum*Yosemite Moon hybrid is losing the oldest growth that flowered last spring. That grow is about three years old. There are still 4 new growth, two of which are sending up flower buds. woo hoo~~ :)
About natural aging, the old leaves would first turn yellow, then starting from the tip, it turns dark brown and dry out completely.
Now, one of my paphs have yellowing leaves (the bottom leaves) that are turning yellow from the base instead of the leaf tip. It is odd, but it is not wet, no fowl smell, plus it is about to open three flowers in a few days, so I don't want to disturb it.
I hope it is fine.

Regarding roots, I will post a new thread soon. I think of all the orchids I have, paphs have quite strange look to their roots. They simply look rotted to me at a first glance. but they were perfectly fine!

The pleated leaves, and the cell collapse would indicate to me that the plant is not getting enough water. It could be from bad roots or not watering often enough. The first two pictures of the last 3 looks like the beginning of fungus to me. How's the air circulation?

Paph roots by nature are brown and hairy. As long as they are firm they're fine.

Terri- Do you have paph whose leaves get pleated along the vein like the one in my picture due to underwatering? I've seen oncidiums leaves accordian when underwatered, but the direction of pleating is not along the vein. So I though it was strange.
I order my plants quite often, so I doubt they are suffering from being underwatered.

I'm not sure about how good the air circulation is here in the apartment. I don't leave the windows open any more as it is getting too cool, and there is no fan running either.