DANIEL SMITH Watercolour Masking Fluid is easy to use with the bottle applicator, the included 5, fine-point applicator tips or with an inexpensive brush.Masking Fluid makes an impervious barrier to protect your watercolour paper and preserve the white areas by blocking watercolour washes from flowing into areas you don't want leaving crisp, clean edges.DANIEL SMITH Masking Fluid applies as an off-white colour and dries to a transparent caramel colour so that you can see it while working, and still be unobtrusive while working on your painting.After Masking Fluid has dried, easy to remove with a rubber cement pick-up or even with your clean fingers.Be careful though, about leaving oils from your fingers when rubbing off the dried Masking Fluid, as oils from your fingers can interfere with new applications of watercolour.Once the Masking Fluid had been removed, either keep the white areas white or add fresh watercolour onto the preserved white area to retain maximum watercolour luminosity.Tip: Don't shake the Masking Fluid, as this may cause air bubbles that will get into the applicator tip and transfer into your Masking Fluid line.Our Masking Fluid does not need shaking because our latex mixture does not easily separate.If you feel you need to mix, then gently roll your bottle once or twice across your table.When applying, gently squeeze the bottle to start the flow of Masking Fluid out the applicator tip.Also, keep the bottle inverted so that the capillary action once started continues to flow and rinse out the applicator tip immediately after using to prevent clogging when it dries.To remove Masking Fluid, use a Rubber Cement Pick-up rather than your fingers to avoid getting oil from your fingers onto your watercolour paper.