Maybe after dotting, use a small brush to spread the glue which would thin it a little and maybe be able to wash out better. I use Sharon Schamber's method with the boards.

That is interesting. I've never had that problem and I am about 12 quilts in with the glue basting. It seems to wash out of all my quilts no problem. I just run it on a regular wash cycle because that's what recipients will do. I don't use fabric softener liquid

Never had the Elmers's School glue do that. It washed out completely. I use a regular cycle, large fill, warm water. The quilt is completely submerged.

Oh, that's so pretty...I really like that! I love the quilting pattern on it too. A great way to use up leftovers and scraps. I think I've got enough to make about eleven-teen dozen placemats! ;)

Have you re-washed the placemat yet?

I always dilute the washable school glue. At least 50-50. It squeezes out better that way, too, and full strength is not necessary.

I had one quilt that showed the spots after I washed it on cold, light wash, no soap. Then I washed it again on Normal with warm water and some detergent, and it all came out.

Soaking would sure help, too.

Maybe it's just the fact that the fabric is plain; whereas, it wouldn't be as noticeable on prints. I agree with others that another wash or a good soak in warm water may take out the rest.

Just a thought ---- could it be the fabric that is the problem? In the photo of the placemat it looks like only the coral color fabric is glue-stained. Maybe that fabric had some kind of finish or something in it to cause the problem?

I usually wash in cold water but I found that when I washed my quilts that I glue basted in cold water it didn't all come out. I now wash in warm water to get the glue out and that works.
I think with the newer water efficient washers as well there might not be enough water to get it out. Another washing and it should be gone. I've never had any left after following these two bit of advice.

I haven't had a problem with the glue since I haven't used it yet but I had a problem with spray starch on 2 different solid fabrics. They were 100 % cotton like all my others but it left big blotches like your glue did. It eventually washed out but it has to be something in the fabric itself I think. Even though we always use 100% cotton , we can't verify if it is all processed the same or the dye used in the fabric is all the same. I would try washing again but I don't think it is the glue. I think it is some sort of reaction with that particular fabric. Maybe the dye in it or something. Who knows but I know I had the same problem with the spray starch. Am I making any sense? lol