Help! My Patterns Are Growing...


My panels always grow, even though I use pattern shears. Should the pieces, once cut and ground, fit in the white part of the pattern leaving the black lines to represent lead or foil?

That is exactly where the pieces should fit. But as you have found out, sometimes thats easier said than done. Lets take a look at all the places your pieces can grow:

1) Making a copy of your pattern for cutting out pattern pieces. First, determine if the line width on your pattern is appropriate for copper foil or lead. When tracing the pattern, try a few different felt pens until you find one that is the appropriate width for the technique you are using. The wrong width pen may cause the pattern pieces to be either too big, or too small. A good way to determine the appropriate width is to make some test cuts using your pattern shears. (There are two sizes of shears, one for lead and one for copper foil.)

2) Cutting out the pattern pieces. Using the appropriate pattern shears, remove the black line (which represents the foil or lead). If you dont use pattern shears, be sure to cut the entire black line away.

3) Tracing your pattern pieces onto the glass. Once your pattern pieces are cut to the correct size, you will be tracing around each pattern piece onto the glass. Most felt tip pens will smear when writing on glass, making it hard to know exactly where to cut. Your supplier carries pens that are specifically designed to stay on glass without smearing. Do yourself a favor and try one if you havent.

4) Cutting out the pieces. This is most likely where your particular problem lies. In the last step, you traced around the paper pattern. This makes the lines on the glass slightly larger than the size you need. Ideally, you want to keep what is inside the line. You do this by cutting along the inside of the line. If you cut down the center of the line, youll need to grind the remaining black line away.

5) Checking your fit. Now place your pieces on a copy of the pattern and check the fit. You should see the black lines between each piece. Look for places where the glass pieces are touching each other. Thats where youll need to do a little grinding. Do any final adjustments before foiling or leading your project.

Now that you are aware of all the places that your project can grow, you should be able to make adjustments to perfect your technique. Good luck!

Reprinted with permission from Stained Glass News. All rights reserved. Pattern pictured also courtesy of Stained Glass News. Download it here.

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Frankie G.  •  April 01, 2011
If you use a copy machine always make two copies and do not use the original and a copy. Although you may think that you are reproducing the image the same size oftentimes it is larger than the original by a fraction. This can be an issue, the larger the piece the more it "grows". Hope this helps.
Stained Glass News

Stained Glass News

Stained Glass News is a full-color newspaper which has been dedicated to informing, entertaining and inspiring stained glass hobbyists for over 22 years. Each issue features: • information on new books, tools and glass • quick tips & hints and Q&A's • columns on stained glass, mosaics, and hot glass by industry experts • photos of our readers' projects in the Readers' Gallery • glassworking hints from our readers on The Readers' Page • a photo and information about a glass workshop belonging to one of our readers on The Readers' Page • other information that makes working with glass easier, more fun and more rewarding SGN is published five times a year (on the first of January, March, May, September and November). The current issue is SGN #90 (May, 2010).