Rebecca opted to have her tattoo removed by laser, a technique now being offered by an increasing number of high street dermatology clinics. It works by using powerful beams of coloured laser light to turn the ink, using heat, into tiny particles. Red and green lights are good for breaking down black, brown and dark shades of green and blue, while red works on purple and orange colours. The particles are then absorbed into the body via the bloodstream, and excreted via the liver and digestive system.
Lasering is a lengthy, expensive procedure - costs vary, but the average is about pounds 200 a session, with the number of sessions dependent on the size and colour. Nor is it ever guaranteed to remove a tattoo completely.
"Historically, the only way to get rid of a tattoo was to cover it with skin-coloured ink, or cut it out. But we can now offer laser techniques with differing degrees of intensity," explains Danielle Young, aesthetic manager at the private Epsom Skin Clinics where Rebecca was treated.
While a conventional laser is passed over a tattoo just once on each appointment, the latest technique, called the R20, enables the beam to pass over the skin four times a session, with 20-minute gaps for the skin to cool.
Although it is hot enough to cause blisters and pain, the laser doesn't cause long-term surface damage.
"Most people feel it as a hot, sharp and fast sensation," says Danielle.
"It is more uncomfortable than having a tattoo, but not so uncomfortable that clients don't want to come back for their next session."
Most people need a course of treatments, which have to be staggered up to eight weeks apart to allow complete healing in between, although for those who have the R20 laser, the treatment works more rapidly.
So is it worth it? Rebecca, who began her treatment last autumn, says: "I have had eight sessions of R20 now, and frustratingly there is little change. I am disappointed as I felt sure it would have begun to go. The clinic think that brown ink must have been mixed with the black originally, and that we will now have to switch to a more suitable laser. So I guess I will just have to carry on. I will have spent about pounds 1,000 in the end. I just want it gone now."
Danielle warns that some people will always be left with "ghosting" - a shadowy outline - depending on the size and colour of the original design. Moreover, lasers that will remove certain blues or light greens, or pale colours like yellow or pink, do not yet exist (although they are in development).
Nor are lasers recommended for darker skins, as there is a risk that the laser will strip out natural pigmentation and leave white scarring. Furthermore, some tattoos may have caused skin scarring during the initial ink tattooing process, which can be revealed only after the colour is stripped out.
Claims are also being made for an alternative therapy in which special liquid is injected into the tattoo, just as the ink was initially. The liquid is said to bond with the colour pigments, and both are then broken down and excreted by the body, leaving a scab behind that should heal.
The treatment is cheaper than laser, but Stuart Harrison, the director of Oxford Skin Clinics, admits that it isn't suitable for old, deep or overly large tattoos. "It would end up being very expensive and removal could take years," he says.
Tattoo removal is rarely carried out on the NHS. Prof Harry Moseley, head of the department of plastic surgery at Ninewells Hospital and Medical School, Dundee and head of the British Medical Laser Association, says: "We do carry out tattoo removal at our NHS clinic, but only in a small number of cases where the patient is severely distressed."
The side effects of laser removal can include not only pain but ongoing skin sensitivity and infection, which is why it is vital that therapists are properly trained. Prof Moseley would like to see all laser operators required to "demonstrate necessary knowledge and skill" and belong to a registered profession, so they "could be struck off if they were negligent".
Not everyone agrees with the claim that laser is just "uncomfortable".
Like Rebecca, Charley Monroe, a 24-year-old receptionist from Croydon, had a tattoo on impulse five years ago.
"I instantly regretted it - my 'design', a small piece of tribal-style art on my forearm, looked awful straight away."
However, she gave up on laser treatment after one session.
"I had never felt anything so sickeningly and excruciatingly painful as those 10 minutes when the skin was under the laser. I couldn't imagine doing that again one more time, let alone 10 more times."
Charley went to consultant plastic surgeon Paul Banwell, whose private cosmetic surgery clinic in East Grinstead offers surgical removal of tattoos. Surgical excision is not new, is no cheaper than laser therapy (an average tattoo might cost pounds 850-pounds 1,400 to remove), and ultimately takes as long. However, it is painless, since it is carried out under local anaesthetic, and the tattoo is guaranteed to be removed completely.
Mr Banwell removed Charley's tattoo in a "serial excision" procedure comprising four different surgeries spaced out over two and a half years, starting in late 2010. The gaps in between the surgeries allowed for healing and skin to stretch again. The excision literally involved cutting out the pieces of ink-stained skin in stages and stitching the area back, to leave minimal scarring.
Mr Banwell says: "There are limitations to surgical removal; it wouldn't work for large tattoos, where the skin is naturally taut, or where the whole of a limb is affected, such as with a tattoo 'sleeve' on the arm. The only way to get rid of a large tattoo by excision would be to treat it like a tumour removal or burn treatment, so that means cutting out all the affected skin and then using a graft to repair the hole.
"It would leave significant scarring, but there are patients who are so traumatised by their tattoos that they will go to those lengths."
In the future, it is possible the hi-tech skin substitutes used in burns units may be used to build new skin.
Charley Monroe says now she is immensely relieved that her "hideous black blotch" has gone forever.
"I can forget all about that mistake. I feel liberated."