There are plastic tanks, stainless steel tanks, and hard chrome tanks. Any of these tanks can handle both barrel plating and rack plating.
Plastic tanks are made of plastic materials like Polypropylene, PVC, CPVC, HDPE while stainless steel tanks come in high-quality steel ]and either lined with plastic or plain. Hard Chrome tanks are also available with titanium or Koroseal lining.
There are many advantages to using plating tanks instead of brush plating. At least you can handle multiple operations in the tank.
About tank liners, instead of using PVC to make the shield, manufacturers use LFP CrossFilm, a 100% PTFE Teflon that has higher mechanical strength than the normal PTFE Teflon. Also, tank liner that last longest, use Koroseal PVC liner with LFP CrossFilm skirt.