When the loop holder (loop could be taped or Araldite to a stick) is held in normal operating position, perhaps 70° from the horizontal, then the loop part should be horizontal. Place the loop under water at the back of the trough, then move to the floating sections and bring the loop up and out of the water. The loop picks up the surface drop of the water, including the sections.

Grids for receiving sections should sit (I prefer dull side up) on filter paper. Use a mounted needle or a tine of pointed tweezers to hold the grid down on the rim. Lower the loop onto the grid and the water will be sucked into the paper and the sections positioned nicely on the grid.
This method is especially useful if you have problems with folds. Sections may be rounded up on the surface of the trough using a mounted hair. I also like a pointed and mounted Teflon sliver, because sections don't stick to it.

The second method is good when you have a single large ribbon to pick up. Orient the ribbon on the water to be in a suitable position. Length of the ribbon can be cut by 'poking' a joint in the ribbon with a Teflon sliver - without the whole ribbon sticking to it, as it may do using a mounted hair.
Pick up a grid from a filter paper with good tweezers by the rim, dull side up. While in contact with the filter paper bring the tweezers up into 'handling position' - thereby bending the rim of the grid.

Insert the grid at the back of the trough and move then to below the ribbon. Now angle the front of the grid up by about 30° in relation to the horizontal and bring the grid slowly up so that a part of the first section of the ribbon will go down on the under (wrong) side of the grid. As you lift the angled grid vertically from the trough the remaining ribbon will lay across the grid nicely. Touch the grid to a filter paper. Incidentally, a wetted filter paper more easily starts to pull the water from a grid. If the tines of tweezers are wet, you will need to hold the grid down when releasing the tweezers.