Found a few online places that sell plastic pegboard. One site described the holes as 1/4". I think this may be too big for my application. I have forgotten how big the holes are that I drilled in my acrylic sheet, but I think they are smaller than 1/4". May have to go with the abs plastic sheet.
As it is now, only about half of the holes I drilled have water going through them on my drip tray. I figure if the holes are smaller, the water will spread out more evenly on the tray. Would 1/8" holes work better?
Someone mentioned side walls on the tray. This had crossed my mind and I think I will try to make some. The current tray fits in well in the end with the most flow so there isn't too much water seeping around it.