I don't know why, but I have a vague memory of BLMA making this product. I don't find it online though, so it could be me just thinking of alternate uses for the grade crossings sets.
JTT makes a 1:250 and 1:200 diamond tread pattern sheet, though it's not the standard plate use in the US. Or you could use that sheet as a master for Marklinofstudios white glue tactic if you wanted the diamond space to be raised.
I watch a lot of Japanese modeling on YouTube and, IIRC one video presented such a product - but I don't recollect which YouTUber and don't speak Japanese to know the details. I know a couple of the Japanese YouTube modelers I watch have done station platform projects (passenger rail being so big in Japan) and they have techniques worth looking at. IIRC, one used a taped off edge of grout of sand painted yellow to create the effect. The Japanese modelers I watch most often are Susukuma, Shigemon, Mihune Studio, and Cityscape Studio. All of those guys do some good modeling and some interesting Japanese-specific detail products cross the screen from time to time. Susukuma is the most prolific and is videos offer English translation using the YouTube feature. The others I just watch ith the volume low and play Grasshopper.
