When using a black backing, I suggest using black batting.

Scrim side should be down. If you aren't sure about this, I suggest contacting the batting producer. If the scrim appears to be more in the middle, then it really doesn't matter.

If you're referring to thread pokies versus batting pokies, than I agree with the above poster, it's a tension issue. It takes a bit of practice to be able to use different colors in the top and bobbin, and a thick batting definitely helps with this issue.

It has to be the batting as I am using black thread on both top & bobbin. I flipped the batting and still have the same problem. Any other ideas?

Try a smaller needle?

Loosen the tension on your quilt. You don't want it to be trampoline tight. See if that helps, in addition to a new needle. A dull needle will poke the batt through.

I've always called that bearding. And have had similar problems. (Used warm and natural both times - which says it's guaranteed not to beard.)
FIRST: I have one quilt with a black back - it bearded - and it is still showing batting fibers through the back - 10 years later. It did not eventually go away or anything; and It's been washed several times)
SECOND: I have a black, white and bright quilt with a black back. We kept changing needles etc. Still bearding (ripped it all out). I finally discovered that I needed to use black batting to camoflage the problem. I knew I had plenty of white on the front and didn't want to gray it out, so I basted a very lightweight white material to the top of the black batting amd it worked beautifully. Is this what you're getting?

Here is the quilt after we fixed it - We used varigated black and white thread and as you can see, you can't see any bearding at all. And the colors are still bright. Real happy with the solution.

Hope this helps.

Smaller needle perhaps?

It's called "bearding" when the batting pokes through. I think it will relax when it's off the frame and the holes will close up. You can test the theory by taking the tension off the sandwich and spritzing the backing with water. Let it dry a while and see if the batting is still poking through.

I had it happen while I was quilting once and it was like little explosions coming up through the quilt top. It would also shred my thread. I think I just got a "dirty" batt. The cotton gin mustn't have been working well the day that batt was processed. Anyway, after the quilt was off the frame & washed, you'd never know that it had been such a beast to quilt.

I just saw M.I.Late's problem child! I would not have been a happy camper! Somebody at Warm & Natural would have gotten a nastygram from me had that been my quilt!

I've got one on the frame now with a black backing and lots of black on the front but I didn't have a black batt to load at the time so I went ahead and used a Hobb's 80/20 unbleached that I had on hand with no problems.

Tension being how tight the quilt is stregthed on the frame?

Wow learned alot thanks everyone