Black and white bumps on Phal orchid.

[Selmo]

Probably edema (water blisters) caused by the plant up taking more water though the roots than the leaves can transpire. Ussally will not cause much harm to the plant, other than the ugly bumps on the leaves. But can become an entrance/vector for diseases and fungus to enter the plant. Remember good fundamentals, good water quality, correct lighting, fresh media, and always good air movment. Best of luck