Warts and all
The whole thing; not concealing the less attractive parts.
This phrase is said to derive from Oliver Cromwell's instructions to the painter Sir Peter Lely, when commissioning a portrait.
At the time of the alleged instruction, Cromwell was Lord Protector of England. Lely had been portrait artist to Charles I and, following the restoration of the monarchy in 1660, he was appointed as Charles II's Principal Painter in Ordinary.
Lely's painting style was, as was usual at the time, intended to flatter the sitter. Royalty in particular expected portraits to show them in the best possible light, if not to be outright fanciful. Lely's painting of Charles II shows what was expected of a painting of a head of state in the 17th century. It emphasizes the shapely royal calves - a prized fashion feature at that time.
Cromwell did have a preference for being portrayed as a gentleman of military bearing, but was well-known as being opposed to all forms of personal vanity. This 'puritan Roundhead' versus 'dashing Cavalier' shorthand is often used to denote the differences in style of the two opposing camps in the English Commonwealth and subsequent Restoration. It is entirely plausible that he would have issued a 'warts and all' instruction when being painted and it is unlikely that Lely would have modified his style and produced the 'warts and all' portrait of Cromwell unless someone told him to.
We have Cromwell's death mask as a reference. From that it is clear that Lely's portrait is an accurate record of Cromwell's actual appearance.
Despite the plausibility of the account, there doesn't appear to be any convincing evidence that Cromwell ever used the phrase 'warts and all'. The first record of a version of that phrase being attributed to him comes from Horace Walpole's Anecdotes of Painting in England, with some account of the principal artists, 1764. Walpole's authority for the attribution came from a reported conversation between John Sheffield, Duke of Buckingham, the first occupant of Buckingham House, now Buckingham Palace, and the house's architect, Captain William Winde. Winde claimed that:
Oliver certainly sat to him, and while sitting, said to him - "Mr Lely, I desire you would use all your skill to paint my picture truly like me, and not flatter me at all; but remark all these roughnesses, pimples, warts and everything as you see me, otherwise I will never pay a farthing for it."
That was published in 1764 - over a hundred years after Lely painted Cromwell. Walpole included no evidence to support the attribution, nor any explanation of why no one else had mentioned the phrase in the preceding hundred years - this despite Cromwell's life being the subject of minutely detailed historical research and over 160 full-length biographies. We can only assume he was indulging in a piece of literary speculation rather than historical documentation. The first known citation in print of the actual phrase 'warts and all' is from a 'Chinese whisper' retelling of Walpole's story - an address given by an Alpheus Cary, in Massachusetts, in 1824:
When Cromwell sat for his portrait he said, "Paint me as I am, warts and all!"
It may well be the case that Oliver Cromwell preferred portraits of him to be accurate, but it is most unlikely that he ever uttered the words 'warts and all'.
See also: the last words of Oliver Cromwell.
See other well-known misquotations.