Tumbling Blocks Afghan

http://www.lionbrand.com/patterns/80263AD.html?keywords=noImages

optical illusion-

Crochet chart makers and instructions on how to read charts

Crochet chart makers and   instructions on how to read charts 

http://stitchworkssoftware.com/crochet-charts

http://www.crochetdesigns.com/software/default.htm

http://www.nhswinc.com/gpage.html

http://kiwiped.com/free-crochet-pattern-software-2/

https://inkscape.org/en/

http://adriprints.blogspot.com/2010/04/how-to-use-stitchin-crochet-with-adobe.html

http://www.craftyminx.com/2011/11/crochet-school-lesson-21-reading-crochet-charts.html