Part of Resident Evil is to save as few times as possible. In fact, in the ones where you get a grade (the remake doesn't grade you) saving actually penalizes you!
Unfortunately, if you've saved 21 times then you've used 7 ink ribbons already... While I can't say for sure, your chances of finding another one anytime soon is slim. But I'll try to name a couple you may have missed.
1. In the desk in the room on the first floor that contains the broken shotgun. (Through the balcony of the dining room, then through the furthest door, the one with the stairs, go down the stairs and the room I'm referring to is in that hallway.)
2. In the main hall there is a room on the right side that's locked by the helmet key. At the far back of the room and to the left is a small desk that contains one.