Because i have so little time to the final crit I have tried several different solutions at the same time in the hope that one of them will work. I tried PVA glue layered on top of areas where only small amounts of chipping has occurred.
However, I found that the glue reacted with in ink making it practically opaque. so the next thing I tried was a layer of clear nail varnish. This seems to work really well and even help regulate the consistency of the colour.