Frugal marbling tools

As I continue my marbling adventures, I find myself needing a variety of different tools, called rakes or combs.  These are the things used in marbling to make fine lines and curves of the paint on the marbling medium.  By using these in sequence and in different directions, the various traditional marbling patterns are created.  The patterns I want to use as a base for my marbling drawings require some of this traditional patterning.  Here's the final stage of my most recent experiment with the Nonpareil pattern as the starting point.  This was done using a hand-dyed silk hanky about 12" square and colored a medium-light blue with a greenish tint.  What I'm looking for is the curved feather that is most apparent in this pattern in the lower left and extending across the middle.

The above pattern requires 3 sets of rakes with different spacing for each set.  Each set is two rakes, one of each length to match the different sides of my marbling tray.  These rakes are also expensive when bought from supply stores because they're made of wood, with really good metal bits.  And they need to be the right size for the trays being used.  So, my frugal streak got creative and I have successfully made them from corrugated plastic sheeting or foam core for the bar part and T-pins or straight pins for the metal parts.

The black one on the left is some scrap foamcore cut about 1/2" wide and about 1/2 the spacing  less than the length of the tray.  The shortness is because the rakes are offset halfway going in the different directions.  The corrugated plastic is scrap from a friend's booth display and has the advantage of being waterproof.  These each took about 10 minutes to make with my handy cutting mat and ruler, and I can get the pricier version once I know what sizes and spacing I need to do the work I like.  For now, as I experiment and learn, this is a really quick and frugal approach.