A Good Fit for Stained Glass: How Close Should the Pieces Be?

​​A Good Fit: ​​What to look for before soldering

​It's a common question asked by many stained glass ​hobbyists, "How close should the glass pieces be?"

​And one would think there should be a straight forward answer, right? 

Well, in theory yes. But I'd rather talk about reality.

We're not machines. We each work differently​, learn differently and have a different amount of patience. And our tolerance for imperfection or drive for perfection​ also varies from person to person.

Although there isn't one simple answer to the reality of this question, ​let​'s discuss 4 different ​situations.

So let's see... You've cut your glass and ground it to fit. ​The copper foil has been applied and now you're getting ready to solder. You push everything together and usually come to one of the following conclusions:

  1. That doesn't look like it fits as tight as it did when I was grinding the glass...
  2. You start to question if whether that gap is too big or not?
  3. You ponder the idea of leaving a little space between everything so that the solder fills it up and makes it stronger.
  4. You look it over and say "Yep, good enough"

Let's break each scenario down shall we?

​1. There are Uneven Spaces Across the Whole Project

​Often, hobbyists will notice that foiled projects fit differently than they did before they were foiled, and they're right. It will always ​fit slightly differently as the foil takes up​ a hair width of space. You won't notice it as much on a suncatcher with only 12 pieces, but start working on a panel with 100 pieces and you'll quickly see a difference.

Th​is minor variance of one hair width will compound with the higher number of pieces in your project as there will naturally be more copper foil taking up space. Think of it this way, one hair width is barely noticeable, but the width of one hundred hairs will make you take notice.

​ For the average glass crafter, the problem with glass fitting differently after foiling isn't usually due to the copper foil. It normally stems from not realizing that things weren't quite lined up when they were grinding the glass. ​Let's say that when you're grinding, you test the fit of piece "A" next to the neighbouring pieces "B" and "C" and everything shifts ​just a little, you might think that "A" fits perfectly. When in all actuality, "B" and "C" are no longer in their ​correct ​position.

I​f this happens with a few pieces in the project, you'll be ​quite disappointed when you line everything up to solder and see that nothing fits the way you thought.

How to Prevent Uneven Spaces

There are a couple of things you can do to try and avoid the problem of uneven spaces between your glass pieces.  

  1. Use push pins or jigs to hold your glass in place while testing the fit. This will prevent other pieces from slipping out of place without you noticing.
  2. Sometimes a piece of glass may have been accidentally flipped over or upside down. A square for example, may not be perfectly square and if turned 90 degrees, could fit very differently. Avoid this by labelling your pieces clearly so you always have them in the correct orientation.

​2. There is a ​Big Gap

​Do you really need to worry about ​it? Can't you just fill it with solder? There won't be a hole anymore ​so no one will see it. Right?

Well, big gaps present their own unique problems and it isn't true that it won't be noticeable. 

When we look at stained glass windows​, they're normally back lit. The glass lets light through while the solder doesn't ( obviously!) So this creates dark lines in our designs. Well, that big hole you want to fill with solder will be visible because it's going to be a large dark space among all of your beautiful solder lines!

Also, have you ever tried to solder a large hole? You need so much solder to fill it, which gets really hot when soldering. When you try to do that final pass, it will likely melt through. You could chase that solder all day back and forth from one side to the next. It's a real pain in the neck!

Another problem which can occur when there is so much heat in one area is thermal shock. Imagine soldering your project and feeling a sense of accomplishment as you near the end only to hear the dreaded "tink" of glass cracking. 

I've been there.

Planning a repair on a piece that isn't even finished yet is heartbreaking. 

The Best Fix for a Large Gap

I'm sure you don't want to hear this but... ​simply put; you need to cut a ​NEW piece.

​If the space you need to fill is bigger than the original ​pattern piece from the drawing, make a new template of the space you need to fill before cutting a larger piece of glass.

​3. Should I Spread​ the Pieces Out?

​Many times newer stained glass workers think that more solder means the whole piece is stronger. Please don't buy into this line of thinking; it's false!

​The reality is that using more solde​r:

  • ​will make your work heavier than necessary,
  • ​will cost you more money​ (solder isn't exactly cheap) 
  • ​won't make your project stronger, only reinforcing it will​

The​re is No Reason to Spread the Glass

​​What you'll want to do it push all of the glass pieces together before soldering. They should ​be touching all along each side as best as possible. This is where getting a good fit while grinding is very important.

​4. "Yep, Good Enough" vs. "The Perfect Fit"

​Is there really such a thing as "The perfect fit" with stained glass?

It can seem ​allusive​ to many. Even experienced stained glass crafters struggle from time to time. But yes, it is out there.  You may not have found it yet​, but don't give up.

We keep pushing ourselves to get the perfect fit because it's what is going to give us the best results for our finished piece. It makes uniform solder lines in our work and, it's a challenge ​that keeps us pushing our skills.

​As with everything hands on, we learn as we go.

When you're starting out, give yourself permission to learn. Accept that things won't be perfect​ but keep aiming for perfection. ​ As you see your skills increase over time, you'll look ​at the challenge of getting the perfect fit as one you're eagerly willing to take on and you'll notice you​r tolerance for gaps in your work will decrease​. 

That's when you can drop the "Yep, good enough" and trade it in for "Ooooh, the perfect fit! Yes!"

Have patience.


And always push yourself just a little bit​.

​Never forget to look back and see how far you've come!

Leave a Reply 39 comments

Patricia - February 15, 2018 Reply

You have got a sense of humour. Thoroughly enjoyed readi g got me down to a T

    Galen Farrugia - June 23, 2018 Reply

    You could definitely see your expertise within the work you write. The sector hopes for more passionate writers like you who aren’t afraid to mention how they believe. At all times go after your heart.

Nancy - February 18, 2018 Reply

Great read and even better advice!

Em - February 19, 2018 Reply

Hi Samantha
Thanks for posting such an informative piece .I really enjoyed it and can identify with every last thing you said. Have been around for many moons,but always feel open to seeing how others do our great craft.Thanks again
Regards Em

Ken Keith - February 24, 2018 Reply

Love the advice. I started using dress maker pins for setting up copper foil pieces, they are thin and long enough to be easy to handle. I get pink foam from the hardware store and pin the pieces. It makes the work stiff enough to stay and light enough to move if I need space.

Great ideas

    Gary Satterlee - August 5, 2018 Reply

    I have discovered a product made by Loctite that is like chewing gum but clean and dry. It will hold the glass very tightly in place but allows you to slide it around slightly. The stuff is strong, totally reusable and a very little goes a long way. I got mine at Staples. I think in the aisle with picture hangers. Try it, you’ll like it.

Les - February 28, 2018 Reply

Great tutorial, I use dress maker pins and cork boards for fitting to pattern and soldering.

Mary Ruble - March 3, 2018 Reply

Wondering what you think of using foiling shears vs just regular. Do they really help or a waste of money?

    Samantha Calder - March 3, 2018 Reply

    Hi Mary, I don’t personally use them. I have a pair and tried many times to adjust to using them. What happens to me is after I make a snip and go to open them to move the shears further into the pattern, the little sliver that they cut out gets trapped in the blades. So when I move, I end up tearing the pattern a bit because the strip is stuck. Many people use them and love them, I just haven’t been able to get the hang of it I guess. For my students in the studio, I suggest that they cut down both sides of the black line for the pattern so that they actually remove it. It may take a little longer but this gives them the little bit of wiggle room they’re looking for.

      Marilynne - July 13, 2018 Reply

      So how thick a line do you use in drawing the pattern to allow for the ideal spacing for foil? Thanks, and very good information.

        Samantha Calder - July 14, 2018 Reply

        Great question Marilynne! The answer will vary depending on skill level. For those starting out, I suggest using an average line width like one would achieve with a thick marker (about 2mm.) I usually get my new students to cut out the black line, just as one would achieve using a pair of pattern sheers. This gives a little bit more play for getting the right fit. For those with more experience and better-refined cutting skills, a 1 mm width line is generally more than enough.

          Tania - December 29, 2018 Reply

          1 and 2 mm sound awfully big. Is that a typo or have I been working with too tight gaps? I hope I can loosen up a bit!

          Samantha Calder - January 4, 2019 Reply

          Hey Tania. Thanks for the question! The question I was answering was in respect to how wide the line should be on the pattern. The answer of 1-2mm is what I find works well for most people in the beginner arena. Since newer crafters haven’t perfected the ability to cut exactly where they want each time, the extra space in the pattern gives an allowance as most newbies I’ve worked with tend to cut the glass on the bigger side (they feel safer doing that.) As mentioned above, over time as skills improve less allowance is needed in the pattern to fit everything together. As for allowing 1-2 mm between each piece of glass, no, we definitely don’t aim for that! That’s exactly why I incuded point #3 in the article.

Jackie walters - March 3, 2018 Reply

Thank you….I appreciate any help that is offered.

    Samantha Calder - March 3, 2018 Reply

    You’re most welcome Jackie.

Lydia - March 4, 2018 Reply

Thank you from a newbie without a class nearby. I am learning from m others like you here on the Internet. This was very helpful as I honey cutting and grinding skills.

    Samantha Calder - March 4, 2018 Reply

    Welcome Lydia! I’m self taught because when I was starting up, there wasn’t as much helpful stuff out there on the internet as there is now, so I totally understand the struggles of going it alone. I’m so happy that you found the article helpful. Just keep in mind that slow and steady wins the race when it comes mastering glass skills!

Caroline - March 4, 2018 Reply

Thank for this – very interesting. Been doing stained glass on and off for many years now. I can relate to all the issues you discuss – been there, done that:) so good to see some practical advice.

    Samantha Calder - March 5, 2018 Reply

    Hello Caroline! It’s great to know that you relate to this, I too went through each of these steps. Sometimes we forget that it’s not always just about using the tools.

Marian - March 23, 2018 Reply

Great advice! I love stained glass and finally found a class! My first project was 76 pieces and had to remake 2 of them for bad fit. I totally agree PATIENCE!!!

    Samantha Calder - March 24, 2018 Reply

    Thanks Marian and yes, patience is key! That’s a hefty sized first piece… 76 pieces? WOW!!! Good for you.

Levticus Bennett - March 30, 2018 Reply

I didn’t know that having a gap in stained glass can cause soldering to melt through. Stained glass looks really beautiful to me, I appreciate the time that artists put into it. Since I don’t know how to put stained glass together I am going to see what professionals can do.

    Samantha Calder - March 30, 2018 Reply

    Hello Levticus. It can happen, but once it cools it is normally touched up on both the front and back so no one would ever know that it melted through in the first place. The gaps just makes it a pain to work with. 😉 You never know… maybe if you gave it a try, you might love it!

Robert W. Sipkema - April 11, 2018 Reply

Hi Samantha Calder, I really enjoyed reading your article. I am new and have been struggling with the grinding and getting the pieces to fit together. This was very helpful. I wanted to watch the video and I signed in to gain access….but it will not open up the video. What am I doing wrong? Thank you for your help. Bob Sipkema

    Samantha Calder - April 11, 2018 Reply

    Hello Bob. I’m glad you enjoyed the article and found it helpful! I’ve double checked your sign up for the soldering video and everything seems ok. I don’t know what went awry, but I’ve gone ahead and sent it to your email again. Have a look to see if it arrived.

Pat tomchek - April 14, 2018 Reply

Could not access video. Thanks

    Samantha Calder - April 14, 2018 Reply

    Hi Pat, An email has just been sent with a link for you to access the video 🙂

Ken Brown - April 21, 2018 Reply

I use small daps of poster board putty on each piece of glass and place them on the pattern as I go. This holds the glass pieces in place on the pattern so you can test how things are fitting. The putty is easy to remove and it only takes a very little to hold the glass pieces in place.

    Samantha Calder - April 21, 2018 Reply

    Great idea, Ken! Thanks for sharing.

get - June 9, 2018 Reply

It’s hаrɗ to find well-informed people about
this topic, bᥙt you seem like you know what you’re talking about!

Betty - June 10, 2018 Reply

Loved your blog post. I read some of “me” in there. But have learned, aiming for perfection makes a neater more professional looking piece.

    Samantha Calder - June 10, 2018 Reply

    Hi Betty, Thanks for your feedback. I am a perfectionist at heart and agree that striving for perfection motivates me too. From teaching many different personalities, I’ve also seen first hand that not everyone flourishes under the stress of perfection and it can actually become a barrier for some people. The distance from where they are to where they want to be can be too daunting or seem so far off that it causes them to give up entirely. Finding what works best for you is key, and it sounds like you have and that’s wonderful to hear!

Max Sayer - June 25, 2018 Reply

Personally, I don’t know too much about leadlight restoration so I wanted to look up some information about them. This article was very helpful when I saw that to get the perfect fit because it’s what is going to give the best result. I think that this is very important and something that I want to keep in mind.

Sandi Morris - August 30, 2018 Reply

Really enjoyed reading this and I just had the problem today that my piece just did not fit good, so I had to cut a new piece! I also realize I probably use too much solder! Thanks for all this great info, Sandi

Kim - September 1, 2018 Reply

I loved this. So much information. Thank you !!!!

Lalit sakhuja - September 20, 2018 Reply

Have been curious to take up the work for beautiful sun catchers, and now after going through the text feel much equipped to prepare for commencing the work . Shall now go collecting the materials.

Harry Ward - November 29, 2018 Reply

Great Blog, lot’s of good advice. When I am soldering I use a paste flux and I have a little container of flux that I use as a sackreficial cleaner for my iron that I can dip the tip into to clean the tip and get rid of the black crusties on it. Once you dip it in, it always comes out clean without using a wet sponge or a cloth.

    Samantha Calder - January 4, 2019 Reply

    Thanks for sharing, Harry. Similar to you, I will occasionally wipe my flux brush across my iron tip (I use liquid flux). As you say, it cleans it like a charm 🙂 Also, glad to hear you’re enjoying the blog too.

Leslie’ - September 27, 2019 Reply

I am a newbie, but am addicted. Really enjoyed your comments and encouragement. Thanks.

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