What is the best paper to print official documents, like a POA, on?

Any regular office paper of decent quality will do. Make several copies. Were I you I would do this with an attorney. He or she will give you the POA papers, keep another original. This POA will not be questioned where the "home done off the internet may be" and this POA will be complete, and cover all you need, for instance selling properties and so on. I did this when my brother made me POA and Trustee of Trust, we both were there, we both were interviewed. It is a strong document. At home, go ahead and make a few copies. Entities are going to want a copy of their own, and may want to make their own copy of the notarized original. You attorney can also make you a letter testamentary type one sheet saying you are serving as POA, and this is often enough to send off in mail to say the utility companies and so on.
If you are doing this for someone already mildly impaired this is important if there are family members who say you had an incompetent person do a POA for you; that wouldn't hold up anywhere as someone must understand what they are doing when they assign POA. A document such as you may be planning, only notarized (which only attests to the signature) doesn't examine the person conferring POA, and may be questioned further down the lane when it is truly too late to change things.
Good luck.

You can't have Mom assign you at this point as POA. With Dementia she cannot sign legal documents. She needs to understand what she is signing. If you think she does, I would have a lawyer draw up the papers. He will question Mom to see if she is competent and understands what she is signing.

My POAs were both typed on heavy ecru colored paper 8x14 which is considered legal size. Both in the same State, different lawyers. Signed by a witness and notarized.

Houseboatbarbie, welcome to the forum. Gosh, your Mom is so young to be having dementia. Have your Mom get an Urinary Tract Infection test {UTI]. An UTI can mimic dementia along with other unusual behaviors. This test can be done at her primary doctor's office or at urgent care.

When my Elder Law Attorney printed out all the legal documents that I needed, it was done on regular copy paper, and also on a computer disc. My POA was 16 pages long.

I am not a big fan of using the internet for legal documents as a do-it-yourself. All it takes is one missing word and/or one misplaced word to create a difficult situation. If you prefer to use on-line, use a company that know what questions to ask for your personal situation, and knows about your State laws regarding a POA. My Elder Law Attorney notifies us any time there are changes to State laws that would require a change to our legal documents.

If you are looking for forms , google legal forms . I forgot which site I used , but I purchased , so they sent me the completed documents. Which was on nice paper…Be choosy.

if you are wondering what type of paper to print it yourself, regular copy paper will do.

Why do you think the type of paper matters? Does Ohio require this?

My Mom printed out PoA docs from Legalzoom.com. On those sites you can ask questions to an actual attorrney that practices in your state. In MN where I live nothing was ever mentioned about the type of paper it was printed on.

My own Living Trust and PoA docs from my private CELA was just copier paper.

I just googled "ohio poa forms" and got several options...