Nylon is usually what the body of the filter is made of. The most important factor is whether it is Hydophobic (bad) or Hydrophillic (good). The most common Hydrophillic filtering mediums are PES -Poly Ether Sulfone, Polyvinylidene fluoride and Cellulose acetate. If you don't plan on using a pre filter which can even include a syringe tightly packed with cotton or filter paper and cotton, then Whatman micron filters are your best bet as they have a glass fiber pre-filter built in that makes them more expensive but also higher on longevity vs the multitudes of much cheaper filters. Remember to get the benefit of bacterial removal from your filter it needs to be 0.22 microns.
Hi,I bet you are from Austria too.I recently bought Rotilabo Nylon 0,2 (μm) micron Filters, they are ok for their price i only paid 38€ for a 100 pack with shipping from ebay. I regret now that i have so long not used micron filters. Even street heroin is so cloudy if not micron filtered, it is disgusting. I mostly use them on 200mg substitol (morphine sulphate). I prefere the millex gp filter 0.22, but they are much more expensive (prohibitively expensive in my opinion).