Take a look at the stripes on the leaf of this paph seedling.

Does this appear to be mechanical/chemical, or do you think i should test the plant for virus? It's a healthy seedling otherwise, a multi cross.

the stripes appeared as the new leaf was emerging, they are just on this leaf.

http://img8.imageshack.us/img8/4992/img4918b.th.jpg (http://img8.imageshack.us/my.php?image=img4918b.jpg)

http://img6.imageshack.us/img6/5153/img4919b.th.jpg (http://img6.imageshack.us/my.php?image=img4919b.jpg)

http://img6.imageshack.us/img6/7541/img4920q.th.jpg (http://img6.imageshack.us/my.php?image=img4920q.jpg)

If it's only on one leaf I wouldn't worry too much.

Never seen this kind of damage.Do you water also the leaves?because the horizpnthal line is strange...usually ilnesses tend to develop the other way...maybe when the water stay in the middle of the plant while the leaf is developping,damage the new tissue forming a line, so maybe something in the water.
Maybe you have done 2 -3 different treatments in short periode of time,that mixing together made reaction causing the damage on the "line of water" in the middle...then growing made more visible the damage.
If not maybe a virus but never seen that kind of virus if exists.
I will separate the plant from others and see next new leaf how will grow.

Looks to me to just be a little growth anomaly. I wouldn't worry too much about it unless the condition worsens.

Thats really interesting i have never seen anything like that!!

I'm with the others, I wouldn't worry about it. On one leaf is no problem.

Remember Paphs can't get a virus (well from what I've been told) so it won't be anything like that either.

I have odd leaves come out all the time.

I agree it is probably not a virus. I think it might have been from application of pyrethrin or more likely water in the crown like Alex suggested.

I am pretty sure paphs do get virus, although less than other orchids. I've read that one difference is that a virused cattleya can live on for decades, while a virused paph will get sick and die when infected. I don't know if i'm spreading misinformation here though. I worry about virus in my collection especially with expensive divisions. just for my own sanity, i plan to do some spot testing of my plants. at $5 per test it is not too much.

I agree it is probably not a virus. I think it might have been from application of pyrethrin or more likely water in the crown like Alex suggested.

I am pretty sure paphs do get virus, although less than other orchids. I've read that one difference is that a virused cattleya can live on for decades, while a virused paph will get sick and die when infected. I don't know if i'm spreading misinformation here though. I worry about virus in my collection especially with expensive division. just for my own sanity, i plan to do some spot testing of my plants. at $5 per test it is not too much.

Seriously I've been told that Paph's can't get a virus at all by a nursery. if they can I really need to know!

paphs are infected with less frequency because they are not commonly divided with tools like cattleyas and other orchids, and they are not cloned from meristem cells

i take precautions in my own collection, avoiding:

letting water drip from plants hanging above
reusing tools to cut leaves on different plants
reusing media and bleaching pots before using again
keeping phal and cattleya orchids separated from my paphs

It looks harmless but nothing wrong with spending $5 for a test to find the truth. Better to spend $5 than to lose a whole collection of expensive plants!

What I have heard is that Paphs do not get mealybugs and those kinds of diseases as much, but they carry viruses more frequently. I don't remember where I read that, but I am thinking it was around about 6%.

Seriously I've been told that Paph's can't get a virus at all by a nursery. if they can I really need to know!

Unfortunately all living beings can get viruses.
Paphs are more subject to "mushrooms" and bacteria and less to parasites.
Disinfection of "tools" is best way to prevent virus spreading(for all orchids).