On Tuesday, September 19, 2017 at 6:15:54 PM UTC-5, JBI wrote:
I have two small shadowboxes, one made from barnyard wood and the other walnut.
Could I paint the frames with shellac?

Yes. Watch for drips if you brush it on. Sealcoat comes in aerosol/spray cans, also.... may be easier to spray projects as these.

Optional:
The barnwood box, my preference.... I like the weathered-wood look, for some things. Consider leaving it raw wood, no sealing. You can always seal it later. Similar examples: Vertical planter boxes I made for the local Master Gardeners' fund raiser. Scroll right for more pics - https://www.flickr.com/photos/438361...in/photostream

Sonny