The more I researched this, the more confused I became.
I found this web stretched in the crotch of a dead pear tree in our backyard. The day was cloudy. I had no idea what the “line” was in the center of the web.
Then I found a smaller web in a clump of sedum. Obviously, it had the same mystery in the center of it too.
This was an even closer shot of the center of the web. The silk was so thin it was hard to see.
I didn’t see a spider in any of these webs until today. The bluish shape on the right, near the center of the picture moved. The spider changed its position in the web. It went out from the center and quickly back. I started taking pictures. It was almost impossible to get a focused picture with the small size of the web. My camera kept focusing on the background instead.
I found a position with the leaves behind and showing the spider. At least I solved the mystery of the spider’s location, and that the other shapes are the spider’s egg cases.
P.S. I have found many of these spider and egg cases scattered around the yard.