Definition
The heart is the most popular pattern shell: the stars are glued onto a heart-shaped template placed at the centre of the shell, so that on opening they spread while keeping the drawing, most often in red or pink, sometimes with an outline in a second colour or a pistil. As with the ring, orientation depends on the shell's spin: a heart may appear face-on, at an angle or edge-on, and a single volley shows several versions. Heart shells exist from 75 to 200 mm; they are in great demand for weddings and Valentine's Day, and are also fired in cakes with pattern bombettes. The same technique produces five-pointed stars, smileys, butterflies or letters, under the generic name of pattern shells.
In practice, for the display company
The heart is a commercial effect: clients ask for it, often for a precise moment of the music, and it is billed as such. PyroDesk links the quote line, the firing-plan cue and the pattern-shell stock; PyroSimulator renders the drawing with its random orientations, which avoids promising the client a perfectly face-on heart.