Rainbow Crystal Christmas Trees – Full Recipe Materials : Paper Christmas tree cutouts (you can make them from thick paper or cardboard; two slotted pieces that stand upright work best) Tray, shallow bowl, or glass dish Epsom salt (BEST for fast, dramatic crystals) You can substitute table salt or baking soda, but growth is slower and less fluffy. Warm water Food coloring (multiple colors) Small cups for mixing color solutions Paintbrush or dropper Scissors and markers (optional, to decorate the