[This blog post was written by Emily Rainwater, Conservator for the State Archives of North Carolina.]
How would you fix a torn piece of paper without tape? One way might be to take another, smaller piece of paper and glue it on top of the tear. This actually forms the basis of modern conservation repair work, though Conservators take great care when choosing both the paper and adhesive. The repair paper is usually an extremely thin tissue with long fibers and excellent aging properties, while the adhesive will be non-staining and easily reversible even with age.
Another way would be to sew the tear back together. This is seen more commonly with parchment as it tends to be sturdier and less likely to tear further from the stitches. However, if the paper is good quality and in good condition, it can be sewn as well, as seen in this example from the Northampton County Apprentice Bonds.
If a historic repair is still working and functioning properly, I will frequently leave it intact. However, if it is damaging the paper, either because it has caused a new breaking point or was done using harmful materials, I may remove it and replace it with a more conservationally sound repair. In the case of this Apprentice Bond, both the paper and repair were in good condition, so the sewing was left intact.