Even with care, faults and accidents occasionally happen. Some remedial corrections are possible where non-staining colours have been applied. Hand-made papers are able to stand a lot of working over to remove faults. Correct with a stiff bristle brush to the extent of light but careful scrubbing and a good working paper surface can still be retained. The less tough, slightly absorbent softer papers such as 'Bockingford' respond reasonably well if handled gently. Should the surface texture of the paper suffer damaging abrasions, dark woolly patches will appear when the area is re-painted. Soft papers are useless for vigorous handling. Provided certain opaque muddy combinations of colours are avoided, freshness in appearance can still be maintained.

UNDER or OVERRUN wash edges of local areas. Correct only when dry. Take a small flat dampened bristle brush, held corner-wise and dampen the offending line edges. After a little while blot the the area with paper tissue. Repeat several times, swishing the brush in clean water each time until the untidy overrun wash is neat and clean or the hard edge of the under-reached wash is softened. Apply different parts of the blotter or tissue each time of dabbing to prevent paint transference back to the paper.

1. BACKRUNS are seepage back into an area partly dried or a wash unintentionally super-imposed on too dry a wash. A backrun resembles a lichen fungus where the pigment has lifted and drifted to form a ridge and it is difficult to correct. The local backrun ridge can be removed with a narrow wedge-shaped sponge, repeatedly dabbing and washing the sponge clean each time and/or lift off with a bristle brush on edge if it is not too seriously affected.
2. BLOTS on dry white paper are caused by a spillage from an overfull brush or an unsteady hand. Correct immediately, blotting them off with a paper tissue or a clean damp brush. Where blots occur on a previously painted area, wash and blot the area several times with clear water until the edges blend with the under-painted wash.
3. SPOTS OF FLOATING PIGMENT may be picked off with the point of a damp round or bristle brush provided the area is not too badly affected.
4. STREAKS AND BREAKLINES are most likely to occur when dark colours or a thick, less watery paint is applied. Causation:

If a wash, whether flat, graded or varied has been applied in too deep a tone, it should be left undisturbed. Any slight unevenness will disappear and the wash will become lighter in tone with an increase in transparency. When the paper is bone dry use a wedge-shaped sponge and clean water to gently remove any streaks in the area affected. Further over-painting will not disturb the original wash. At all times it is best to work directly and freely, resisting the temptation to 'touch up' parts that have already been painted. There are times when an area must be left to dry before passing on to the next local area. At other times allow one colour to flood into and blend with an adjacent colour which is not the same as going back and touching in an area that still remains wet. With time and experience knowledge accumulates and critical powers develop.

• Colour washes applied too dark and too dryly. Insufficient paint in brush
• Unvaried colours of foliage, tree trunks, branches, bricks and tiles etc.
• Colours dispensed directly from tubes or pans
• Lack of tone control
• Shadows falling in different directions from the parallel rays of sunlight or the same direction from a radiating light source
• Weak foreground. No attention to the undulation of the land
• Flat cardboard cutout effect due to hard edges on hills and mountains. Softening the edges will go a long way to correct this
• Too much overworking, re-touching and over-painting
• Accents too dark and not enough contrasts. Too much detail

Note: In some cases where colours have been applied too deeply the watercolour sheet attached to the board can be made thoroughly wet under a water tap. The whole sheet can then be mopped over to blend the colours into a well-integrated base. When dry, local areas may be over-painted with colour without the rawness sometimes associated with over-simplified paintings.

A tiny spot of washing up liquid or oxgall in the paint mixture will cause a wash to run smoothly and evenly. Adding a small amount of glycerine to a paint mixture will retard the drying time and tend to keep the pigment floating on the surface of the paper. This is an obvious advantage when 'lifting off' is required for a correction. The disadvantage, a longer drying period is needed, slowing the various stages of the picture .