Can a torn watercolour be repaired?
Tears can be repaired in your watercolour by a series of different treatments. Paper fibres, although fine, can be rewoven to integrate losses. Alternatively, infills or patches can be applied to the piece following careful examination and sizing to fit the exact loss.
In addition, a conservation standard, stable, inert adhesive/paste may be applied. For example, a common treatment would be to conduct a tear repair with Japanese Paper and methyl cellulose paste.
Crucially, the stability of any material applied to your original watercolour must be ensured in order to avoid risks to the safety of the original. Any material added to your watercolour should be of similar weight and aesthetic to integrate with your piece.
Can Sellotape be used to fix tears in my watercolour?
Self adhesive tape (sellotape) is not recommended to repair tears as tape has poor ageing properties and becomes difficult to remove. Consequently, it threatens the long term stability of your watercolour. This method is unsympathetic to your watercolour, in both an aesthetic and structural sense, and alternatives as mentioned above would be recommended.