Marshall Photo Oils MS4CBX Chinese Blue - EXTRA STRONG - 3/4 Inch x 4 Inch Tube for Accessories Overlay oil colors on toned retouched prints to produce other colored effects Apply Photo Pencils over in combination with Photo Oils Applying Photo Oil colors over Spot-All Dyes after liquid has dried Apply oils in a light to heavy range with brush palette knife. photo; oils; photo oils; Marshall; Marshall's; retouching