1. Cover tray with wax paper.
2. Place chocolate chips and shortening in medium heat-proof bowl. In separate large heat-proof bowl, put very warm water (100° to 110°F.) to 1-inch depth. Carefully place bowl with chocolate into bowl with water; water should come halfway up side of chocolate bowl.
3. Stir chocolate and shortening CONSTANTLY with dry rubber scraper until chocolate and shortening are melted and mixture is smooth. *Do NOT get water in bowl with chocolate. (If water cools, replace it with very warm water as directed above; water temperature is important to success). Remove chocolate bowl from inside water bowl.
4. With fork, dip chilled centers into chocolate mixture, one at a time; gently tap fork on edge of bowl to remove excess chocolate.** Invert coated center on prepared tray; swirl small amount of melted chocolate on top to cover fork marks; let stand until firm. Store candies loosely covered in cool, dry place. Coating for 4 dozen centers.
* If water or moisture gets into chocolate, it can seize and tighten. As an emergency measure, ONLY, stir in additional shortening, 1/2 teaspoonful at a time, just until chocolate is fluid again.
** If chocolate mixture cools below 84°F, return bowl with chocolate into bowl with warm water. Chocolate is best for coating between 84° and 88°F.
CHOCOLATE CANDY IN MOLDS: Melt chocolate with shortening as directed above; remove bowl from inside water bowl. Spoon chocolate mixture into plastic candy molds; let stand until firm. Invert molds over prepared tray; tap candy from molds onto tray. Store as directed above. About 4 dozen 1x1-1/2 inch candies.