'3-d circles' - from my new favourite art ideas website called Our Art Lately and it was on THIS optical illusion artwork post that I found it.
I printed out some instructions and my pupils worked on their art as a reading/art activity for a DIY task. We used crayons or colouring pencils for the colours rather than felts.
Here are some of the results from my Year 5 and 6 pupils: very important to get the shading right in the whiter blocks to get the effect.
We also found this activity from the blog Art With Mr E and enjoyed the effect that it creates! We used A3 cartridge paper and black vivid pens (with newspaper underneath to protect the tables) - draw one curved line side-to-side across the A3 paper, then place about 8 dots randomly-spaced along the curved line.
Next, use the vivid to join the dots with small curved lines. Repeat the movement, being sure to run the pen right into the dot each time (to build up a dark shadow line between each tube). Keep going until sheet is full. Try to not let the lines cross over (the Mr E blog post has examples of what NOT to do).
Once the lines are created, select three or four coloured pencils and begin shading the segments of the 'tubes' - aim for about three shades of the colour within the segment - we coloured the section all over very lightly first, then pressed more firmly about a third of the way in from each side, then pressed even more firmly in the very corners of the segment, so we had a gradual build up of colour - it is important to shade side-to-side within the segment, not to run the pencil up and down or you might make edges or lines.
More examples to come!!