Every once in a while, I receive questions from interested artists and craftspersons about paper. The following is one that I truly enjoyed answering.

I am writing to you to ask for an opinion. I belong to an organization of artists who all work on or with paper. At a recent meeting the question was raised whether Yupo, Mylar, acetate, Tyvek, and similar synthetic substrates would be accepted by our group as forms of paper. This led to a very lively discussion and opinions were all over the place.

What are your thoughts on the subject? Do you know of any consensus within the art/museum world?

Here’s my answer:

Many people will consider almost any 2-dimensional substrate to be “paper,” but from a purist perspective, true paper is formed from cellulose that has been beaten, dispersed in water, and then is reformed on a mould surface. We’re not picky about the surface that this new mat of cellulose fibers has been formed on, but simply that they are cellulose, they have been broken apart (generally very finely), and then reformed.
Materials like papyrus, or even amate (a beautiful substrate originating in Mexico), is what we refer to as proto-paper. This term indicates that the original cellulose structure was never broken apart entirely. With papyrus and amate, the plant is prepared by cooking or retting, and then strips of the plant fiber are simply overlapped and pounded or pressed together to form new hydrogen bonds in the cellulose, which create the single sheet. This sheet is more fragile and less flexible than a true paper.

People will also ask if making a mat of wool, hair, or silk can be considered a paper, however, anything with a protein base is felt, and is not paper.
Likewise, Yupo, Tyvek, mylar, acetate are all synethtic as you point out and petroleum-based. Therefore, not true paper. These materials certainly have their uses, even within bookmaking (and I really enjoy using them for certain projects) but I will always make a point of including those specific materials in the description of an artwork, i.e. watercolor on yupo; OR ink on handmade paper and Tyvek.

As for art world / museum consensus, my above definitions are accepted or acknowledged, but in many cases a watercolor painting on yupo will be considered for an exhibition of works on paper. This decision can depend largely on the juror or curator, whether they are a purist, an inclusionist, or simply interested in the image regardless of the substrate, so long as it’s 2-dimensional.

As for IAPMA, we tend to be purists, and we promote the use and inclusion of paper in artworks, in particular of handmade paper.

Although it still may not settle the argument, I hope this answers your question!