The top and bottom halves that join together to form spheres have little to no seam that forms a seal, to get a solid sphere you need the entire Fill cavity with water so the weight will stop the balls from leaking and the water will fill the balls after the silicone's lack of rigidity causes a lot of spills on the way to the freezer. I would recommend a different product but if you are stubborn they will work
SMARTAKE Non-Stick Parchment Paper Roll, 13 In X 164 Ft (177 Sq. Ft) For Baking, Cooking, Air Fryer, Steamer, Kitchen, Cookies, Bread, And More - White Baking Pan Liner
41 Review
4 Pack 12 Inch Stainless Steel Round Pizza Baking Pan Tray Crisper Sheet Oven Cooking Healthy For Pizzas - Deedro
47 Review
2-Pack European Grade Silicone Bunte Cake Pan Set - Non Stick Bakeware Fluted Tube Mold For Jello, Gelatin & Cakes | 9 Inch Baking Pans | Aokinle | BPA Free
38 Review
PME Scriber Needle Modelling Tool, For Cake Decorating, 5.7-Inch
38 Review