C2 Exterior Solid StainC2 Exterior Acrylic Solid Stain provides outstanding protection from the harshest weather while still showing the texture of the wood. It can be applied directly to new wood as long as any mill glaze is removed prior to staining. However, a primer should be used if its a staining wood such as cedar. C2 Exterior Solid Stain is our best selling vertical siding and shingles stain.