Ronseal Ready Mixed Hairline Crack Smooth Finish Filler Available in 100g & 330g tubes & a 600g tub. Fine particle size ingredients fill gaps up to 5mm wide Reduced sanding, super smooth finish Applies smoothly for an invisible repair Ready to decorate in 1-2 hours Developed to fill cracks up to 5mm wide, it's guaranteed not to shrink or crack. The finely blended filler particles gives a supremely smooth finish creating an invisible repair to your walls.