A variety of film-forming solutions are available to prepare support films and replicas of smooth surfaces.

Formvar (polyvinyl formal) is normally used as a 0.25% solution in chloroform.
The thickness and stability of the film can be altered by adjusting the concentration between 0.25% and 0.5%.

Pioloform is polyvinyl butyral dissolved in chloroform (0.3 – 1.5%).
The solution should be stored in a refrigerator in an amber glass bottle, and brought up to room temperature before use.

Butvar B98 is a polyvinyl butyral resin containing 20% polyvinyl alcohol, and is normally used as a 0.25% solution in chloroform.
It is an alternative support film to Formvar as reported by: Handley and Olsen, Ultramicroscopy 4, p479 – 480, 1979.

Films made from Butvar are hydrophilic, and are therefore suitable for negative staining methods, having good mechanical stability, high electron transparency and minimum intrinsic structure.

Butvar B98 can also be applied to grids as an adhesive.

MSDS

Download Material Safety Data Sheet – AGR1201 & AGR1202 Formvar

Download Material Safety Data Sheet – AGR1275 Pioloform

Download Material Safety Data Sheet – AGR1276 Butvar

Download Material Safety Data Sheet – AGR1277 Silicon Monoxide