GoFuckYourself.com - Adult Webmaster Forum - clear answer about paypal please...

It's in the PayPal AUP on their site.

Mature Audiences Policy

Unless you are completing a transaction on the eBay Mature Audiences site, you may not use PayPal to sell or purchase "adult" or "sexually oriented" material.

How does PayPal define "adult" or "sexually oriented" material?
"Adult" or "sexually-oriented" material includes, but is not limited to:
Any visual representation of human genitals presented in such a manner as to suggest sexual activity.

Any visual representation of any form of sexual intercourse involving humans

Any materials which require that individuals be eighteen (18) or older (depending on the jurisdiction) to view or purchase those materials

Any non-textual materials clearly designed to sexually arouse the viewer/reader

Any items which, because of their nature or because of the item description, appear to be designed for use in sexual/adult activity

Any items which dhahahahat human sexual characteristics in a degrading fashion

Any item that portrays frontal nudity will normally be treated as "adult" material
What is not considered "adult" or "sexually oriented" material?
Material that is not considered "adult" or "sexually oriented" includes but is not limited to:
That which is a small and insignificant part of a catalog, book, periodical, or other work which is not, as a whole, primarily devoted to sexual matters

Books or other text without pictures, as long as the material is not obscene, even if designed to sexually arouse the reader

Pieces of artwork that may be considered fine art-such as certain paintings, carvings, figurines and other similar materials. Examples include, but are not limited to, Michelangelo's David, certain (but not all) vintage pinup art, a renaissance-style painting of a nude female, or nude cherubs in the form of human infants (in the style of Raphael)
Can material containing nudity ever be sold using PayPal?
Yes. As long as the material containing nudity is not considered "adult" (as defined above) and fits into one of the categories below, you may use PayPal to sell the material, and you may sell or advertise such material on your website listed in PayPal Shops:
Movies & Videos
PayPal permits the sale of movies that may be viewed by individuals age 17 and under to be listed in this category. This includes movies rated PG, PG-13, and R, which often contain some nudity or sexual situations

Collectible Risqué Postcards
PayPal permits the sale of postcards that contain some nudity but are not "adult" or "sexually oriented" (as defined above). While persons portrayed in postcards may be topless, scantily clothed, or in mildly suggestive poses, any postcards sold using PayPal should not dhahahahat male or female genitalia (frontal nudity below the waist) or strong sexual content. Because this category is for collectibles, these postcards should be at least 10 years old, and the description of the item should include the approximate year of publication

You may only use PayPal to buy or sell materials that portray genitalia, pornographic postcards, and postcards that are less than 10 years old if you list these items in the eBay Mature Audiences section, subject to eBay's Mature Audiences policy

Collectible Pin Up Art
PayPal permits the sale of pinups that contain some nudity but are not "adult" or "sexually oriented" (as defined above). While persons portrayed in pinups may be topless, scantily clothed or in mildly suggestive poses, the pin ups in this category should not dhahahahat male or female genitalia (frontal nudity below the waist) or strong sexual content. Because this category is for collectibles, these items should be at least 10 years old, and the description of the item should include the approximate year of publication

You may only use PayPal to buy or sell materials that portray genitalia, pornographic pin-ups, and pin-ups that are less than 10 years old if you list these items in the eBay Mature Audiences section, subject to eBay's Mature Audiences policy

Pre-1980 Adult Magazines
PayPal permits the sale of old adult-oriented magazines that have become collectible for their mixture of nudity, journalism, and art. The only magazines included in this category are Playboy, Playgirl and Penthouse magazines which were printed before 1980

You may only use PayPal to buy or sell newer (post-1980) adult-oriented magazines if you list these items in the eBay Mature Audiences section, subject to eBay's Mature Audiences policy

Pre-1940 Risqué Photographs
PayPal permits the sale of photographic images that contain some nudity but are not "adult" or "sexually oriented" as defined above. While persons portrayed in these photographs may be topless, scantily clothed or in mildly suggestive poses, the pin ups in this category should not dhahahahat male or female genitalia (frontal nudity below the waist) or strong sexual content. In addition, these items should be published prior to 1940, and the description of the item should include the approximate year of publication

You may only use PayPal to buy or sell risqué photographs that portray genitalia, pornographic photographs, and post-1940 photographs if you list these items in the eBay Mature Audiences section, subject to eBay's Mature Audiences policy

Risqué Gag Gifts & Novelties
PayPal permits the sale of certain types of adult novelty items. Such items may include various types of toys, collectibles, or food items in the shape of genitalia primarily intended for adult buyers (unless the item requires the buyer to be 18 in order to purchase.) Examples of items that are permitted include soaps, certain food items (such as pasta or candy) and key chains

You may only use PayPal to buy or sell gag gifts and novelties which do not meet the above requirements, if you list these items in the eBay Mature Audiences section, subject to eBay's Mature Audiences policy. These items may include, but are not limited to: items which are intended for use in a sexual setting (such as "bondage" and "fetish" items), items which display sexual activity or portray human genitalia in a "life-like" or realistic fashion, and vibrators intended for use in sexual activity (as opposed to ordinary massagers)