in toolkit/jb/shared.js [896:910]
function drawBackground(p, config, ctx) {
var productId = config.product;
if (!productId) return;
var width = config.width;
var height = config.height;
//p.blendMode(p.NORMAL);
if (cachedImages[productId + '/bg'] && ctx && productId!='empty0') {
ctx.save();
ctx.rotate(config.angle);
ctx.scale(config.scale, config.scale);
ctx.drawImage(cachedImages[productId + '/bg'], config.x || 0, config.y || 0, width, height);
ctx.restore();
//putLogoAt(ctx, , logo.x * width, logo.y * height);
}
}