You can make paper and ink
Consider the examples given by Fabricate:
For example, you can fabricate a wooden bridge from a clump of trees, a rope from a patch of hemp, and clothes from flax or wool.
Do you think making paper or ink is significantly more difficult than making a bridge, a rope, or clothes?
No way. Making clothes is by far the most difficult task. Not only do you need to process the flax or wool into thread, but then you have to magically weave it too.
If all you need to do is record spells, you can certainly grab some sticks and leaves from the ground and form them into paper, and prick your finger and form the blood into ink. I'm sure you could pick up a twig and form it into a pen too.
The limitations of course are:
The quality of objects made by the spell is commensurate with the quality of the raw materials.
You need high quality fibres to make high quality paper.
You also can't use it to create items that ordinarily require a high degree of craftsmanship, such as jewelry, weapons, glass, or armor, unless you have proficiency with the type of artisan's tools used to craft such objects.
You probably can't create some kind of artisan embossed special paper or fine ink without proficiency.
This doesn't much help a wizard
Your book is presumably already made of paper, so that's a good start. But, the Wizard spellbook rules state:
For each level of the spell, the process takes 2 hours and costs 50 gp. The cost represents material components you expend as you experiment with the spell to master it, as well as the fine inks you need to record it.
Creating a "fine ink" is probably quite difficult and expensive. You can create the ink yourself for a discounted price so long as you have an appropriate proficiency and expensive enough materials.
However even if you can make the ink, you still have to pay for the other material components to practice the spell.
A Hand Book on Wood: Identity and Necessity
: you may see the related passage in google books tinyurl.com/sb29w22 \$\endgroup\$