Example

function setFontSize($fillColor, $strokeColor, $backgroundColor)
{
    $draw = new \ImagickDraw();

    $draw->setStrokeOpacity(1);
    $draw->setStrokeColor($strokeColor);
    $draw->setFillColor($fillColor);
    $draw->setStrokeWidth(2);
    $draw->setFont("../fonts/Arial.ttf");

    $sizes = [24, 36, 48, 60, 72];

    foreach ($sizes as $size) {
        $draw->setFontSize($size);
        $draw->annotation(50, ($size * $size / 16), "Lorem Ipsum!");
    }

    $imagick = new \Imagick();
    $imagick->newImage(500, 500, $backgroundColor);
    $imagick->setImageFormat("png");
    $imagick->drawImage($draw);

    header("Content-Type: image/png");
    echo $imagick->getImageBlob();
}