I am getting somewhat confused about Kant's stance about ornaments. In the Critique of Judgement, Kant seems to make a strict distinction between parergon (the add-ons to say cruely) and ergon (the work itself) in section 14. But he also uses ornaments such as wallpapers as examples in his explanation of what makes something beautiful. So can ornaments be beautiful, in Kant's view? And if so, does that make them art? And if not, why not?
Providing the quote for context
So, let us have a look into the text proper. I will provide a full quote of the important part of section 14 (translation and non-academy pagination from the Cambridge edition, 2000, trans. by Paul Guyer and Eric Matthews).
Even what one calls ornaments (parerga), i.e., that which is not internal to the entire representation of the object as a constituent, but only belongs to it externally as an addendum and augments the satisfaction of taste, still does this only through its form: like the borders of paintings, draperies on statues, or colonnades around magniﬁcent buildings. But if the ornament itself does not consist in beautiful form, if it is, like a gilt frame, attached merely in order to recommend approval for the painting through its charm – then it is called decoration, and detracts from genuine beauty. (5:226, pp. 110-11)
Before we get into details about the quote itself, there is also a note about the term parerga:
The parenthetical term parerga, a word in both Latin and Greek meaning something subordinate or incidental, is added in the second edition. (p. 110, note i)
What is translated as "ornament" in the above quote is "Zierath" in the German original and distinguished from "Schmuck", which is correctly translated as "decoration".
Lost in translation and the second textbit mentioned
Especially for readers of the Cambridge Edition, the wording might be confusing, since "ornament" only occurs the two times in all the book, which are covered in the quote above: The point where Kant again uses "Zierath" (or the synonymous "Verzierung") in the original as an example of painting in the broad sense (5:323) is translated here as "decoration", i.e. exactly the thing that "detracts from genuine beauty" (5:226) according to the first quote:
To painting in the broad sense I would also assign the decoration [Verzierung] of rooms by means of wallpaper, moldings, and all kinds of beautiful furnishings, which merely serve to be viewed; likewise the art of dressing with taste (rings, pill boxes, etc.). For a terrace with all kinds of ﬂowers, a room with all sorts of decorations [Zierathen] (even including the ﬁnery of the ladies) constitute, at a splendid party, a kind of painting, which, just like painting properly so called (which does not have the aim, say, of teaching history or knowledge of nature), is there merely to be viewed, in order to entertain the imagination in free play with ideas and to occupy the power of aesthetic judgment without a determinate end. (5:323, p. 201)
Discussion and Conclusion
As you can see from the first quote, Kant is clear in distinguishing ornament [Zierath] proper from (mere) decoration [Schmuck]. The former has beauty in itself if it is "external" to the object, but still directly "augments the satisfaction of taste [...] through its form". The latter - it is implied - may make something look more precious (hence "gilt" frame), but does not add to beauty since it lacks the form necessary to do so.
In the second quote, the glitch in the translation only adds to the confusion, since Kant is clearly speaking about ornaments proper, not (mere) decorations here: He speaks of how (ornamental) forms, even in tapestries or the finery of women, may constitute an appearance similar to paintings of art, i.e. induce the purposeless free play of imagination through their forms.
Hence, Kant is quite consequential and consistent in his wording (at least in German, duh!) and meaning here: All he is saying in both quotes discussed here is that all perceptible (here: visual) properties of objects may constitute beauty proper if they have the appropriate form to do so. Even if they are only "parerga", i.e. subordinate to the object proper and thus must be called ornamental.
Therefore, since the paragraph from which the second quote is taken begins with "[t]he art of the painter", ornaments proper are to be counted as art according to Kant. The sentence directly after the second quote confirms that:
The work in all these decorations may be, mechanically, quite different, and require very different artists; but the judgment of taste concerning what is beautiful in this art is determined in a single way: namely, to judge of only the forms (without regard to an end) as they are offered to the eye, individually or in their interconnection, in accordance with the effect that they have on the imagination. (5:323-24, p. 201)
[[Ironically, Kant here has a glitch as well: "all these decorations" is "all diesem Schmucke" in the original, which really should have been "all diesem Zierath". FWIW, the two are synonymous in "common" language (Zierath is outdated now).]]