If you are trying to find a pen that will write well on glossy paper without smudging. (The paper is like what you might find in a picture book or a yearbook.) Here are some suggestions for what type of pen to use?

It may be hard to find a marker for slick surfaces that won't smear at all just after it's applied.

There are special pen markers that are sold for writing on photographs that work very well though (look in photo depts, or go to photo stores)--they usually sell for about $1-2.

And art supply or craft/hobby stores will sometimes have permanent pens especially for slick surfaces too, and perhaps the drafting sections of some office supply stores. (make sure "permanent" is written on the label)

(And off course, pens made for dry-erase boards will write on slick surfaces, but they won't be permanent either.) 

Try taking some slick paper to any of those places, and try out each pen (try smearing the ink after only a second or two, then after about 10 seconds).

Ballpoint pen ink can be pretty good too, as long as it's not really thick and gloppy ink... and really cheap ballpoints may not flow on as readily.