Last year we started paying a flat fee for paper and copier use at the school's request. I don't see a problem with using school resources without paying for them since you aren't using them to benefit yourself, but are doing it to help the school. If you don't feel comfortable with your situation, offer to pay the school for the use of their supplies.
We use the school's copier but provide our own paper. The school has discussed billing us for copies made but I haven't seen a bill for it.
We also use part of a storage closet, electricity, air conditioning, heating, phone, etc.
We do not use office supplies such as envelopes, stamps, paper, or whatnot unless they are given to us to perform some sort of project for the school.
I think you might be trying to make these lines to distinct when, in most cases, parent groups are extensions of the school and why we allowed to come into the school to do our work recruiting, fundraising, meetings, and, in return, support the school as much as is fiscally and ethicly possible.
The irony of commitment is that it’s deeply liberating-in work, in play, in love. The act frees you from the tyranny of your internal critic, from the fear that likes to dress itself up and parade around as rational hesitation. To commit is to remove your head as the barrier to your life. --Anne Morris
non profits can also use school grounds for free (for meetings and such) so maybe paper copying is in the same ballpark, free to a non profit, 'use of machine' at least, epecially one who provides services for the sole benefit of the school.
Maybe you shoudl pay for the paper, but thats up to your princiapl.
We use the school's copier and regular white paper. When we want to use color paper, we provide our own (but still use their copier).
Everything our PTO does is for the school or an extension of school programs. I don't see any conflict in using those supplies as long as the school is comfortable with it.
If you realy want to go 'by the book', maybe your principal could pass this question by the district legal counsel, or ask the CPA that audits your books.
We use the school's copier and paper and have offered to pay for it, but they don't bill us because they figure they are getting the cost back and then some with all the money we put into the school. There are other schools in our area that simply pay a flat rate per school year for copies so they have the convenience of being able to use the school copier. We have purchased paper at times for special projects that required colored paper.
Talk with your principal and see how he/she feels.