I get the June Tailor brand at Joann's. It it adhesive spray that washes out. I'm sure this is what your instructor wants you to use.

I too think it is what is called basting spray and Jo Anns carries the June Tailor here too. I do like other brands such as Sullivans, better. I get it from Hancocks.

There is june tailors, sullivans, 505 and they are basting sprays. I think adhesive is a little different

I USE 505 spray . it's the best

I like 505, but there are less costly that are just as good.

I buy the June Tailor brand from walmart....10 oz can for $8...works great for me, but must remember that a little goes a long way....with nobody to show me, I used way too much the first time and had a mess.....I can now do 4-5 lap sized quilts from one can and have no issues....I can even sew down the edges and trim off any extra batting/backing with no problems....after using the spray correctly, I will never pin baste again!

I've used it but don't use Dritz. It totally gummed up my machine. I had to PULL the quilt top from the batting and backing and wash everything to start over again. I was shocked at how heavy the spray was as I have used the other sprays

I used Dritz for embroidering towels because I couldn't find the 505. It was awful. I barely sprayed it on the towel to adhere it to the stabilizer (and I tried it both ways). After I removed the towel from the stabilizer, the towel kept sticking to itself. It felt awful. Good thing my sister was going to immediately wash the towels before sending them off to college with my niece!!

I love the June Tailor brand too. All I could find was the dritz and it was just terrible

It sounds like you picked the right spray.
It sure was a shocker to find out how much these can cost. Even with a 50% off coupon at JoAnn's I thought it was a bit much. But now I'm so glad I spent the money, it helped a ton. I had troubles even with using it, but without it, my quilt would have been a disaster.