.mce-content-body img.mce-tinymce-clear-float {
    background: transparent url( '../images/tinymce-clear-float-placeholder.png' ) repeat-y scroll center center;
}

@media print, not all, ( -webkit-min-device-pixel-ratio: 1.25 ), ( min-resolution: 120dpi ) {

	.mce-content-body img.mce-tinymce-clear-float {
		background-image: url( '../images/tinymce-clear-float-placeholder-2x.png' );
		background-size: 1900px 20px;
	}
}