Egglaying Media - Some Research
OK, the following is only from one experiment, with one species, Sepia Pharaonis (Pharaoh Cuttlefish) and may or may not apply to other species.
This experiment was conducted at the Aquaculture Research Center in Thailand, and they found that there was NO PREFERENCE for any particular media - stone, bamboo, plastic, light or dark-colored, etc. They laid eggs on all of them.
According to the researchers, if the eggs are left in a bunch as they were laid, a higher number of eggs will fail to hatch as oxygen circulation around the eggs is important. Therefore they cut the bunches up with scissors (carefully!) and place them in floating plastic baskets to ensure a good flow of oxygenated water. More than 95% of the eggs hatch with this method.