By Leon Watson
If you think these incredible images are photos, think again. They are in fact probably the world's most intricate doodles.
It may be hard to hard to believe but the pictures below are created using standard ballpoint pens bought from places like Staples, eBay, Amazon and, the artist says, any good office supply store.
They're drawn by Portugal-based attorney Samuel Silva, who describes his art as a hobby. However, this is no ordinary hobby - sometimes he works on a piece for up to 50 hours.
Like a photo: Portugal-based attorney Samuel Silva, 29, describes his art as a hobby
Silva has drawn images of wildlife, recreated masterpieces like Vermeer's Girl with a Pearl Earring and copied iconic photos so accurately they're almost indistinguishable from the original.
For his Redhead Girl, based on a photograph by Russian photographer Kristina Taraina, the 29-year-old used six different colored ballpoint pens which took some 30 hours to finish.
To create such vibrant colours, Silva 'cross hatches' in layers to give off the illusion of additional hues and depth.
For Silva, ballpoint pens are just one of the many mediums he is attempting to master. However, he writes on his DeviantArt page: 'I'm just a lawyer, art is just a hobby for me, although it takes from five to 50 hours to finish each drawing.'
Silva, who started sketching when he was two, said: 'I started developing my own style of ballpoint pen drawing back when I was in school, in simple classroom sketches in the back of my exercise books.
Speaking about his picture of a Sumatran tiger, which took around 20 hours to finish, Silva said: 'This one is wild, that's why I love it.'
After finishing this work, Silva said: 'Eight hours to finish. Just another quick doodle. Or call it a study or sketch. My first eagle head ever.'
On this piece, Silva said: 'Originally I intended to spend 100 hours with this, and still I never spent so many hours with any drawing, in the end impatience won and I'll not work on this one anymore.'
'I never imagined there were so many brilliantly masterful ballpoint artists out there. Ballpoint pen is not my only medium, it's just the one I'm currently trying to master.
'At this point in my life I'm proficient with chalk, pencil, color pencil, pastels, oils and acrylics. Maybe one day I'll create an account just to share those.
I'm just glad to be here, I want to learn a lot, see a lot, and enjoy to its fullest what other fellow artists have to share.
Silva said the original size of this drawing of a cat's face is about the same as two credit cards
The painting Girl with a Pearl Earring is one of Dutch painter Johannes Vermeer's masterworks, but Silva copied it using ballpoint
This was Silva's first ever picture of a jaguar. It took him 15 hours to complete
'It takes me forever to do my works. The only thing that makes me keep going is my love for what I do and the ambition to go further and further.
'Ballpoint pens are as underestimated as they are a powerful medium.'
Speaking about his picture of a Sumatran tiger, which took around 20 hours to finish, Silva said: 'I always wanted to draw a tiger, I love felines and decided to draw my first tiger ever, I hope you like it.
'This one is wild, that's why I love it. Big felines are not meant for zoos.'