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Educational ARTicles

There are a lot of good resources on the Internet for learning art! To aid you on your quest, we have gathered some free (and legal) articles / images / videos / books. They are mostly organized by artist, but are not listed within any particular order. Please use the search function in your browser if you are looking for something specific...

Monika Zagrobelna

On both her blog and her Envato Tuts page, Monika has a huge number of articles covering many different aspects of art. For example:

I Want To Draw, But I Don't Know Where To Start
I Want To Draw: Simple Exercises For Complete Beginners
How To Learn To Draw
How To Draw Animals
How To Draw Textures

...and this is just a small sampling. One could seriously get an entire art school education from her articles alone! Even if you already have some skill in art, or are interested in mediums other than drawing, she shares a wealth of useful information.

Joumana Medlej

Joumana has a very helpful Human Anatomy Fundamentals Course based off of her book Drawing People. She also has a couple of excellent courses on Arabic Calligraphy and Geometric Design. Her tutorial diagrams are jam packed with a ton of useful info too. Definitely worth checking out.

Jeff Searle

Jeff runs an interesting blog (though it is not always about art!). His series of posts on drawing heads / doing portraits are real gems. To make them easier to peruse, here is all of them in order:

Fear of Art
Drawing Simple Heads
Introduction To Drawing The Head
The Human Skull
Muscles of The Head & Neck
Constructing The Head
Drawing The Head From Different Angles
The Divided Ball & Plane Method
Proportions of The Human Head
The Features
Drawing The Eye
Drawing The Nose
Drawing The Ear
Drawing The Mouth
The Head In Profile
Planes of The Head
Lighting The Head
Tone On The Head
Drawing Hair
Male & Female Differences
The Head On The Neck & Shoulders
Head Types
Drawing Heads At Different Ages
Drawing Heads: Ethnicity
Facial Expression
Planning A Portrait
A Short Introduction To Light
A Short Introduction To Colour
Colour Relationships
Portraits In Color
Painting A Digital Portrait Step-By-Step

Darlene Nguyen

Darlene has a website, RapidFireArt, with a course on the basics of realistic drawing. If you want to get into photorealistic rendering, it is a great place to start.

Brian Duey

Like Darlene, Brian also has some excellent tutorials on photorealistic rendering.

Niklas Jansson

Niklas gives some good art advice, especially in regards to rendering color. [Note: The same website has tutorials by other artists as well.]

Seiichi Nakamura (中村 成一)

Seiichi is a well-known artist in Japan who shares some interesting figure drawing material on his website. Two important caveats: There is some drawn nudity, and all of the posts are in Japanese! However, the images usually speak for themselves. If you are having a hard time navigating the home page, here is an English translation of the main tutorial links.


Like Seiichi's website above, Kitajima has a lot of helpful figure drawing material, such as photo references of various hand gestures from many different angles. It is a great place to get the fundamentals of artistic anatomy down. There is also a little bit of tutorial text that accompanies some of the images, but it is available in several languages (i.e.: Japanese, English, Mandarin Chinese, and Korean).

Josh Reed

Josh has many images on his website, each of which contains a helpful distillation of beginner art information. He has also recently started making YouTube videos! [Caution: Some of the images have a tiny bit of nudity (both photographic and drawn).]

Meg Wittwer

In addition to illustrating Paul Tillery IV's humorous Thundercluck book, Meg also wrote a fun and informative series of "Tutor Tuesday" articles. They are a nice starting point if you just got into drawing, and some of them might contain a few useful tips if you are already experienced. All of them are available in a download of PDFs categorized by subject as well.

Lorenzo Etherington

One half of the famous Etherington brother duo, Lorenzo has hundreds of art tips in his series "How To Think When You Draw". They are available on multiple websites, but in my opinion, are easiest to navigate on his deviantArt page. If you are interested in writing, his brother Robin also makes the fascinating "How To Think When You Write" series.

Gregory Manchess

Gregory has a series of blog posts called "10 Things..." that covers what he has learned throughout his illustrious career in oil painting. To make them easier to browse, here is a list of them in chronological order [Caution: There is some painted nudity here and there.]:

...To Remember About Training
...I Remember About Planning Paintings
...I Remember About Procrastinating
...I Remember About Portfolios
...I Remember About Tracing
...About Planning Pictures
...About Generating Paintings
...About Talent
...Applying Paint
...About Competitions
...About Adventure Painting
...About Painting In Oils
...Word List
...Painting Book Covers
...About Value
...Painting Like A Writer
...Knowing When To Stop
...Evaluate Your Painting
...Finding Your Audience
...Using Black
...What's In The Picture
...About Reps
...The Business of Illustration
...About Edges
...Painting Priorities
...Sketching the Model
...Horror Portfolio
...Storytelling Pictures
...What You Cannot Know
...About Edges
...Visual Storytelling
...Painting Like A Writer
...Clever Colloquialisms
...The Little Book of Talent
...Painting Portraits
...Mixing Color
...10 Days To A Breakout Painting
...10 Best

Salgood Sam

Max Douglas (who goes by Salgood Sam) is a fantastic comic book artist. His Dynamic Drawing blog has some very interesting articles that are worth reading.

James Gurney

James Gurney (who is probably most well-known for writing and illustrating the Dinotopia series) runs a blog with all sorts of things (e.g.: inspiring pieces of art, demonstrations of techniques, general art advice, and some personal journal-type entries).

Andrew Loomis

Many thanks to nekobusses for reminding me of Andrew Loomis' many useful books. These are classic texts on nearly every aspect of illustration. [Please note that there is a small amount of nudity, particularly within Figure Drawing For All It's Worth.] If you would like physical copies, they have been republished by Titan Books. If you like the "Golden Era" illustrators like Andrew Loomis, you might also enjoy The Famous Artist Course from the 1960's.

Pedro Medeiros

Pedro wrote The Pixel Grimoire, a really good introduction to pixel art. He has also done a ton of one image tutorials on concepts related to pixel art that are really fun to look at.


ArtyFactory is a website with a lot of lessons on appreciation of different styles of art and basic demonstrations of different media.


Handprint is a website with a ton of detailed material on watercolor, color theory, perspective, and a few other topics. Intriguing!


ArtGraphica is a beautiful website with lessons for a variety of different mediums.

DeviantArt Galleries

DeviantArt is filled with tutorials by many highly-skilled artists. Here is a selection of a few gallaries [Caution: There may be some nudity here and there. However, you also probably won't be able to see it unless you specify that you are 18+.]...

Betsy Luntao has written some of the most useful material on perspective that I have ever seen. If you want to know how to apply perspective rather than just theorize about it, then read her tutorials and download her free book. [If you are adamant on spending money to learn perspective, then get Marshall Vandruff's $12 video set and/or Robbie Lee's $20 book Perspective Made Easy.]

Nsio has broken down drawing into a science. He makes a lot of interesting observations and shares helpful advice on how to develop your skill.

DerSketchie gives tutorials (mostly on human anatomy) that are concise and pleasing to look at.

Nova really gets into human anatomy (muscles especially).

AquaSixio covers various aspects of color and light (in reference to digital art).

JohnoftheNorth provides some useful art tips (mainly about rendering and color theory).

Funkymonkey1945 has a huge number of interesting images within his gallery (e.g.: simplified anatomy breakdowns, step-by-step portraits, etc.). However, keep in mind that it can be a little hard to navigate because there are a ton of images, some repeat, and a few share the same titles even though they are different.

...There are similar collections of tutorials on Tumblr as well (e.g.: Lena's Drawing 101)

YouTube Channels

Painting Tube
This website acts like a directory for art videos!

Alma Luna
Alpay Efe
Alphonso Dunn
Andrew Tischler
Art by Galen
Art of Wei
Becca Hillburn
Brushes and Bunnies
Cosmic Spectrum Art
Dan Beardshaw
Dan Nelson
David Chelsea
Dearing Wang
DoKiDoKi Drawing
dP Art Drawing
dr. Draw
Draw like a Sir
Emoco Ch. / えもこ
Ethan Becker
Fine Art Academy
Fine Art-Tips
Forrest Imel
hide channel
Jack Montmeat
John Muir Laws
Josh Art
Kirsty Partridge Art
Krenz's Artwork
Kyle Hefty
Love Life Drawing
Manga Materials [Personal Notes]
Marc Brunet
Marco Bucci
Mark Crilley
Mei Yu
Midlife Artist
Miss Jisu
Pixel Overload
Reagan Doodles
Richard Smitheman
Roberto Osti
Salem Shanouha
Sanjog Sinnarkar
Sara Tepes
高原さと/ Sato Takahara
Sinix Design
Sketch A Day
S. Michael Hampton
STEVE HUSTON Draws from fife
Stephen Travers Art
Terry Moore Art
The Drawing Database

Old Art Books

Open Drawing Books
This website has a lot of books, but not all of them are downloadable.

For Download:

Albert Racinet - Polychromatic Ornament
Allen Seaby - Drawing For Art Students & Illustrators
Anson Cross - Color Study
Anson Cross - Drawing and Painting Self-Taught
Anson Cross - Free-Hand Drawing
Anson Cross - Light and Shade
Anson Cross - Mechanical Drawing
A.P. Boyce - The Art of Lettering
Arthur Bushenell - Storied Windows
Arthur Dow - Composition
Augusto Garneri - L'Ornato
Caroline Rimmer - Figure Drawing For Children
Christopher Dresser - The Art of Decorative Design
Charles Hayter - An Introduction To Perspective
Charles Maginnis - Pen Drawing
Charles Weigall - The Art of Figure Drawing
Ch Crouvezier - Album de Chiffres and Monogrammes
Clothier Franklin Edminster - Architectural Drawing
Combinaisons Ornementales (Maurice Verneuil, Georges Auriol, Alphonse Mucha)
D. Laurent de Lara - Elementary Instruction in Illuminating
Dora Norton - Freehand Perspective and Sketching
Dorothy Furniss - Drawing For Beginners
D.R. Hay - Original Geometric Diaper Designs
Easy Lessons In Perspective
Edmund Gress - The Art and Practice of Typography
Edmund Sharpe - Decorated Windows
Edward Ball - Inventive Drawing
Edouard Cuyer - Artistic Anatomy of Animals
E.G. Lutz - Drawing Made Easy
E.G. Lutz - Practical Art Anatomy
E.G. Lutz - Practical Drawing
E.G. Lutz - What To Draw and How To Draw It
Elements of Lettering (International Correspondence Schools)
Eugene Viollet-le-Duc - Dictionnaire Raisonne Volume 1 [The other volumes are also available.]
F. Edward Hulme - Principles of Ornamental Art
Ferdninad Schraidt - Geometrical Drawing
Frank Atkinson - A Show At Sho Cards
Frank Howard - Imitative Art
Frank Jackson - Theory and Practice of Design
Frank Mathewson - Perspective Sketching
Frederic Goudy - Elements of Lettering
Frederik Macody Lund - Ad Quadratum
Freeman Delamotte - Book of Ornamental Alphabets
Freeman Delamotte - Embroiderers Book of Design
Freeman Delamotte - Mediaeval Alphabets
Freeman Delamotte - Signists Book of Modern Alphabets
G.E. Hicks - A Guide To Figure Drawing
George Trobridge - The Principles of Perspective
G.M. Ellwood - Studies of The Human Figure
Harold Brown - Applied Drawing
Harold Speed - The Practice and Science of Drawing
Henry Shaw - The Encyclopaedia of Ornament
James Page - Guide For Drawing The Acanthus
Jasper Salwey - The Art of Drawing In Lead Pencil
Jay Hambridge - The Diagonal
Jean (Jehan) Cousin - La Vraye Science de la Pourtraicture [Some nice images of the plates can also be found here.]
Jean (Jehan) Cousin - The Book of Fortune
J.E. Paynter - Practical Geometry for Builders and Architects
J.G. Chapman - The Elements of Art
J. Hullah Brown - Sketching Without A Master
J. Humphrey Spanton - Geometrical Drawing and Design
J. Humphrey Spanton - Science and Art Drawing
J.H. Vanderpoel - The Human Figure
Johann Gottfried Schadow - Polyclet (Plates)
John George Wood - Lectures On Perspective
John Henry Parker - An Introduction to the Study of Gothic Architecture
John Ruskin - Elements of Drawing & Laws of Fesole
J. Smith Moyr - Ornamental Interiors
Jules Bourgoin - Les Elements de L'Art Arabe
Lewis Day - Lettering In Ornament
Lewis Day - Ornamental Design
Lewis Day - Ornament and Its Application
Lewis Day - Pattern Design
Lewis Day - The Anatomy of Pattern
Linus Faunce - Mechanical Drawing
Luie Chadwick - Fashion Drawing and Design
L.W. Miller - The Essentials of Perspective
Margaret Reeks - Hints For Crystal Drawing
Mary Merrifield - Handbook of Light and Shade
Max Kushlan - Free Hand Drawing and Designing
M. Digby Wyatt - The Practice of Illuminating
Michel Jacobs - The Art of Composition
M.M. Runciman - Rules Of Perspective
Owen Jones - Examples of Chinese Ornament
Peter Halt - Perspectiuische Reiss Kunst
Practical Compendium of Commercial Pen Lettering
Radford's Cyclopedia of Construction Volume 1 [The other volumes are also available.]
Rene Binet - Esquisses Decoratives
Rex Vicat Cole - Perspective
Rex Vicat Cole - The Artistic Anatomy of Trees
R.G. Hatton - Figure Drawing & Composition
Robert Billings - Architectural Illustrations
Robert Billings - Illustrations of Geometric Tracery
Robert Billings - The Power of Form
Robert Scott Burn - The Illustrated London Drawing Book
Sadakichi Hartmann - Landscape and Figure Composition
S.J. Latta - Hints On Drawing
T.U. Taylor - Backbone of Perspective
U.S. Army - Realistic Drawing
Victor Wilson - Free-Hand Lettering
William Audsley - Guide to the Art of Illuminating
William Bartholomew - Linear Perspective Explained
William Gordon - Loose Leaf Lessons In Lettering
W.J. Loftie - Lessons in the Art of Illuminating
William Thompson - Modern Show Card Lettering
William Walker - Handbook of Drawing
Wooster Bard Field - Architectural Drawing
W.R. Tymms - The Art of Illuminating
Villard de Honnecourt - Album de Dessins et Croquis

For Borrowing:

Adrian Hill - Beginner's Book of Anatomy
Adrian Hill - You Can Draw
Albany Wiseman - Drawing and Painting People
Alexander Kruse - How To Draw and Paint
Alois Fabry - Sketching Basics
Angela Gair - Hands, Faces, and Figures
Angela Gair - How To Draw Anything
Angela Gair - How To Draw and Paint People
Angela Gair - The Artist Handbook
Angela Gair - The Drawing Course
Angela Gair - The Oil Painting Course
Angela Gair - The Watercolor Course
Angelo Grado - Mastering The Craft of Painting
Arthur Guptill - Color Manual
Arthur Guptill - Drawing With Pen and Ink
Arthur Guptill - Oil Painting Step-By-Step
Arthur Guptill - Rendering In Pencil
Arthur Guptill - Sketching As A Hobby
Arthur Guptill - Watercolor Painting Step-By-Step
Arthur Zaidenberg - Anyone Can Paint
Arthur Zaidenberg - Dictionary of Drawing
Arthur Zaidenberg - Drawing All Animals
Arthur Zaidenberg - Drawing Self-Taught
Arthur Zaidenberg - How To Draw Birds, Fish, and Reptiles
Arthur Zaidenberg - How To Draw Butterflies, Bees, and Beetles
Arthur Zaidenberg - How To Draw Dogs, Cats, and Horses
Arthur Zaidenberg - How To Draw Heads and Faces
Arthur Zaidenberg - How To Draw Landscapes, Seascapes, and Cityscapes
Arthur Zaidenberg - How To Draw Military and Civilian Uniforms
Arthur Zaidenberg - How To Draw Motors, Machines, and Tools
Arthur Zaidenberg - How To Draw People At Work
Arthur Zaidenberg - How To Draw Period Costumes
Arthur Zaidenberg - How To Draw Portraits
Arthur Zaidenberg - How To Draw With Pen and Brush
Arthur Zaidenberg - How To Paint In Oil
Arthur Zaidenberg - How To Paint With Watercolors
Arthur Zaidenberg - New Encyclopedia Of Drawing
Arthur Zaidenberg - Seeing With Pencil and Brush
Arthur Zaidenberg - Sketching Is Easy
Arthur Zaidenberg - The Art of The Artist
Aubrey Sykes - Painting With Pastels
Aubrey Sykes - Still Life In Pastel
Barbara Oelke - Drawing and Painting Horses
Barbara Soloff-Levy - How To Draw Aquarium Animals
Barbara Soloff-Levy - How To Draw Birds
Barbara Soloff-Levy - How To Draw Cats
Barbara Soloff-Levy - I Can Draw Insects
Barron's Art Handbooks - Animals
Barron's Art Handbooks - Airbrush
Barron's Art Handbooks - Baroque Painting
Barron's Art Handbooks - Figures
Barron's Art Handbooks - How To Recognize Styles
Barron's Art Handbooks - Illustration Techniques
Barron's Art Handbooks - Impressionism
Barron's Art Handbooks - Landscapes
Barron's Art Handbooks - Mixing Colors
Barron's Art Handbooks - Pastels
Barron's Art Handbooks - Portraits
Barron's Art Handbooks - Romanticism
Barron's Art Handbooks - Still Life
Barron's Art Handbooks - The Nude
Barron's Art Handbooks - Vegetation
Barron's Art Handbooks - Watercolor
Barron's Complementary Themes For Painting Techniques
Becky Hall - You Can Draw Horses
Bernard Chaet - The Art of Drawing
Bob McKay - How To Draw Funny People
Bodo Jaxtheimer - How To Paint and Draw
Carl Schmalz - Finding and Improving Your Painting Style
Carl Schmalz - Watercolor Your Way
Carrie Snyder - How To Draw Dogs
Carrie Snyder - How To Draw Horses
Cortina - How To Draw Animals
David Astin - How To Paint and Draw Animals
David Kershaw - Guide To Portrait Painting
David Millard - The Joy of Watercolor
David Millard - More Joy of Watercolor
Don Bolognese - Drawing Dinosaurs and Other Prehistoric Animals
Don Bolognese - Drawing Horses and Foals
Don Bolognese and Elaine Raphael - Charcoal and Pastel
Don Bolognese and Elaine Raphael - Pen and Ink
Don Bolognese and Elaine Raphael - Pencil
Douglas Graves - Drawing Portraits
Douglas Graves - Figure Painting In Oil
Elliott Ivenbaum - Drawing People
Ernest Seton - Art Anatomy of Animals
Ernest Watson - Composition In Landscape and Still Life
Ernest Watson - Course In Pencil Sketching (Book 3)
Ernest Watson - How To Use Creative Perspective
Ernest Watson - The Art of Pencil Drawing
Ernest Watson - The Watson Drawing Book
Felicity Everett - Fashion Design
Frank Medworth - Figure Drawing
Frank Webb - Watercolor Energies
Fredric Sweney - Painting The American Scene
Fredric Sweney - The Art of Painting Animals
Gill Speirs - I Can Draw Faces
Gill Speirs - I Can Draw People
Gill Speirs - I Can Draw Sharks and Whales
Gladys Emerson Cook - Drawing Wildlife
Gladys Emerson Cook - The Big Book of Cats
Gwen Robinson - I Can Draw Prehistoric Animals
Hans Schwarz - Color For The Artist
Hans Schwarz - Draw Buildings and Cityscapes
Hans Schwarz - Draw In Pencil, Charcoal, Crayon, and Other Media
Hans Schwarz - Draw Sketches
Hans Schwarz - Figure Painting
Harry Borgman - Art and Illustration Techniques
Harry Borgman - Drawing In Ink
Harry Borgman - Drawing In Pencil
Harry Borgman - Landscape Painting With Markers
Harry Borgman - The Illustrators Guide
Hazel Harrison - Pastel School
Hazel Soan - 100 Keys To Great Watercolor Painting
Hazel Soan - The Encyclopedia of Watercolor Landscape Techniques
Helm Wotzkow - The Art of Hand Lettering
Henry Gasser - How To Draw and Paint
H.F. Hollis - Perspective Drawing
Hugh Chevins - Drawing Perspective
Hugh Laidman - Animals How To Draw Them
Hugh Laidman - Figures/Faces
Hugh Laidman - How To Make Abstract Paintings
Jack Hamm - Cartooning The Head and Figure
Jack Hamm - Drawing The Head and Figure
Jack Hamm - Drawing Scenery
Jack Hamm - How To Draw Animals
Jack Kramer - Human Anatomy and Figure Drawing
Janet Rancan - How To Draw Cats
Jeff Crosby - Drawing Horses
Jerome Goyallon - Drawing Prehistoric Animals
Jia Shi Liang - Lessons In Chinese Landscape Painting
Jim Arnosky - Drawing From Nature
Jim Arnosky - Drawing Life In Motion
Jim Arnosky - Sketching Outdoors In Spring
J.M. Parramon - How To Draw Heads and Portraits
Jocelyn Schreiber - How To Draw Fairy-Tale Characters
John Cody - Visualizing Muscles
John Grabach - How To Draw The Human Figure
John Pratten - Portrait Painting For Beginners
John Raynes - Drawing and Painting People
John Raynes - Draw Faces and Expressions
John Raynes - How To Draw The Human Figure
John Raynes - The Complete Anatomy and Figure Drawing
John Raynes - The Complete Drawing Course
Judy Clifford - Drawing Your Baby
Kay Gallwey - An Intro To Drawing Animals
Ken Howard - The Complete Artist
Laurel Hart - Putting People In Your Paintings
Linda Murray - How To Draw Prehistoric Animals
Louis Slobodkin - The First Book Of Drawing
Lucy Smith - How To Draw Horses
Lucy Watson - Figure Drawing
Maitland Graves - The Art Of Color & Design
Martin Pope - Drawing Celebrity Caricatures
Mary Seymour - Draw Flowers and Plants
Mary Seymour - Draw Interiors
Melvyn Petterson - Cats
Melvyn Petterson - Drawing Landscapes
Michael Ffolkes - Draw Cartoons
Michael LaPlaca - How To Draw Boats, Trains, and Planes
Michael LaPlaca - How To Draw Cars and Trucks
Michael LaPlaca - How To Draw Dinosaurs
Michael Woods - Landscape Drawing
Moira Huntly - Draw In Brush and Ink
Moira Huntly - Draw Nature
Moira Huntly - Draw Still Life
Morrell Wise - Drawing With Colored Pencils
Nanae Momiyama - Sumi-E
Nigel Walters - Principles of Perspective
Pamela Johnson - How To Draw The Circus
Pat Clarke - Painting Heads and Faces
Paul Frame - Drawing Cats and Kittens
Paul Frame - Drawing Dogs and Puppies
Paul Frame - Drawing Reptiles
Paul Frame - Drawing Sharks, Whales, Dolphins, and Seals
Paul Frame - Drawing The Big Cats
Paul Hogarth - Creative Pencil Drawing
Philip Thiel - Freehand Drawing
Rachel Rubin Wolf - Keys To Painting Faces and Figures
Ray Prohaska - A Basic Course In Design
Rex Brandt - Watercolor Landscape
Richard Downer - Drawing Buildings
Richard Hatton - Figure Drawing
Robert Beverly Hale - Anatomy Lessons From The Great Masters
Robert Wood - Watercolor Workshop
Robin Capon - Basic Drawing
Robin Lee Makowski - How To Draw Cats and Dogs
Ronald Pearsall - Introduction To Drawing
Ronald Pearsall - Introduction To Oil Painting
Ron Tiner - Figure Drawing Without A Model
Roy Spencer - Draw Children
Roy Spencer - Draw The Human Body
Roy Spencer - Draw Zoo Animals
Ruth Merington - Object Drawing
Sadami Yamada - Complete Sumi-E Techniques
Sadami Yamada - Landscape Sumi-E In Three Weeks
Sally Harper - The Watercolor Artist's Handbook
Samuel Marshall - How To Paint and Draw People
Sandra Angelo - Exploring Colored Pencil
Sandra Angelo - So You Thought You Couldn't Draw
Stan Smith - Anatomy Composition Perspective For The Artist
Stan Smith - Drawing and Painting The Figure
Stan Smith - Drawing: The Complete Course
Susan Meyer - How To Draw In Pen and Ink
Susan Sonkin - How To Draw Baby Animals
Tom Porter - Architectural Drawing
Valfred Thelin - Watercolor-Let The Medium Do It
Victor Perard - Anatomy and Drawing
Victor Perard - Drawing Animals
Victor Perard - Drawing People
Victor Perard - Drawing Sea and Sky
Victor Perard - Hands and Their Construction
Victor Perard - Perspective
Wende Caporale - Painting Children's Portraits In Pastel

This is just a small sampling. Many more can be found on the bottom of each page under the "Similar Items" section.

Academic / Technical Papers

Jocelyn Ireson-Paine - Semantics of Line Drawings [The same author has some other fascinating articles as well, like Improving Visual Memory and Drawing as Translation]
Tilke Judd, Frédo Durand, Edward Adelson - Apparent Ridges for Line Drawings
Stephen L. Talbott - Seeing in Perspective [Chapter 22 of the book The Future Does Not Compute]
The Art of Binocular Perspective [WIPO Magazine - December 2011]
Asmaa Saeed Alqahtani, Lamya Foaud Daghestani, Lamiaa Fattouh Ibrahim - Techniques used to Improve Spatial Visualization Skills of Students in Engineering Graphics Course: A Survey
David Briggs - The Dimensions of Color