Kathleen Fasanella posted a blog back in Feb 2006 about grading rulers. Imagine my surprise when I opened a book I picked up at a thrift store. Inside the front cover was a little used hinged grading ruler in it's original packaging with instructions! The ruler was stashed in an older edition of the Price/Zamkoff grading book. The book was priced at a measly $2 - the original price sticker for the ruler was still on the packaging of $5.35. Funny thing is, I bought the book about 3 years ago and stuck it on a shelf. I only opened it up a few days ago as I was working on my new infant grading charts. I wanted the book as a grading reference, but rarely use it because of how poorly it explains grading. What a great bonus to find the ruler!
About 98% of the grading I do is in a CAD program. Grading on the computer is so easy! Select a point and tell the computer how much growth should occur in the X,Y directions. It redraws the curves automatically. It is easy to double check the grade in the larger sizes by laying the pieces on top of each other or walking the pieces along side.
Every CAD program varies in ease of use. I have done computerized grading using Gerber's Accumark, Autocad/Betacad and Optitex. I will blog in the future about the differences between the three. Suffice it to say, Optitex is the easiest to use thus far, and quickly becoming my favorite. Grading by hand, is another story. It is tedious and takes a lot of time. I can see why grading is considered an art form. I am grading my personal patterns by hand and it is a big learning process.
In design school, I learned to grade with only a ruler. My 18" clear ruler with 1/16" increments, is photographed above. Grading with only a simple ruler is fairly straightforward. You measure out the changes and re-draw your pattern for each size step. Using a grading ruler makes the process so much simpler! I graded my infant flat block patterns with the grading ruler in a couple of hours (I was re-working some of my grades at the same time). The ruler is marked in 1/16" increments. Your grade rules need to be in 1/16", 1/8", 1/4", 1/2" increments to use this ruler effectively, which means you may need to re-work some of your basic pattern measurements to make grading easier.
I hope to demonstrate the process of actual grading, but for now I am enjoy playing with my lucky find!