I am blown away. I had no idea that corn starch could be used as glue. I saw a video where an English lady mixed wheat glue with PVA glue to give you more time to place the materials as you want them. I suppose you could do that here as well...mix corn starch glue with PVA. Thanks so much!
Yup, you can use a PVA mix with corn starch paste too. Personally I'm not a big fan of the mixes. When I use PVA one of the things I'm looking for is for it to grab and hold relatively quickly so don't want to slow that down by adding paste. If I don't need that quick grab then I find that paste provides all the strength I need so no need to add PVA. But I think it is a lot about what you get used to.
I don't have any training as a conservator, so my uninformed perspective is that paste can grow mold before you use it because it is still moist. Wet paper would grow mold as well. I have heard that people do add oils like clove or peppermint but I think that is more about having the paste last longer before using it rather than any benefit of the pasted paper after the paste has dried.
I speak from only limited experience, but I'd be willing to bet that a small amount of borax would go a long way to limiting mold growth. However, I can't speak to what impact that might have on the longevity of paper it comes in contact with.
