How Is Stained Glass Made? The Process, Step by Step

"How did they make that?" Kids tend to ask it the moment sunlight hits a stained glass window and spills color across the floor. Here's the answer, in words you can pass along, and a way to make one together afterward.

Stained glass is made by cutting colored glass to a full-size drawing, then joining the pieces with strips of lead or copper foil and soldering them into one panel. The color isn't painted on top. It's in the glass itself, which is why the window glows when the sun comes through.

Quick Answer

A stained glass panel goes through four stages, and each one answers a question a child is likely to ask next.

1. Design. The maker draws a full-size pattern, called a cartoon, and marks every section with a number and a color.
2. Cut. Colored glass is scored and broken to match each section, then trimmed until every piece fits.
3. Join. The pieces are held together with lead came (H-shaped lead strips the glass slots into) or copper foil wrapped around each edge, and the joints are soldered.
4. Finish. Painted details are fired in a kiln, a leaded panel is cemented to firm it up, and the panel is framed and installed.

Lead came suits large windows where the dark lines are part of the picture. Copper foil suits small, detailed pieces like suncatchers and lampshades.

Table of Contents

• "Why is it so bright?" Where the color comes from
• "Why does old glass look wobbly?" How flat sheets were made
• "How do you cut glass?" The tools on a glass bench
• "What are the black lines?" How a panel is held together
• "How do they know where each piece goes?" From drawing to window
• "Can we make one?" Trying it at home
• Staying safe
• Frequently asked questions

"Why is it so bright?" Where the color comes from

Glassmakers add small amounts of metal oxides to glass while it's molten. Copper can make ruby red, cobalt makes blue, manganese makes purple, antimony makes yellow, and iron makes green. The color becomes part of the material, so it holds as light passes through instead of sitting on the surface like paint.

In kid words: the color is baked into the glass, like food coloring stirred into frosting, so the sun shines right through it.

A finished panel brings together three kinds of work. There's color making (choosing the glass), shape making (cutting and fitting to a pattern), and structure making (whatever holds the pieces together). Everything below is one of those three.

"Why does old glass look wobbly?" How flat sheets were made

A blowpipe turns molten glass into a bubble, not a flat sheet. Medieval glassmakers solved that by blowing the bubble into a long cylinder, cutting off the ends, slitting it lengthwise, and flattening it while it was still red hot. Glass made this way has slight streaks, bubbles, and changes in thickness, which is why old windows sparkle unevenly. Next time you're near one, have your child look for the tiny bubbles.

"How do you cut glass?" The tools on a glass bench

Glass isn't really cut the way paper is. It's scratched in a line and then snapped, which surprises most kids. Cathedral glass is transparent and often textured, opalescent glass is cloudy or milky, and art glass can carry streaks or swirls. The design becomes a cartoon, a full-size working drawing that works like a sewing pattern for glass.

• Glass cutter: a small hardened wheel that scores a line across the surface.
• Running pliers: snap the glass along the score, a bit like tearing along a perforated line.
• Grozing pliers: nibble tiny bits off an edge, like trimming a rough cookie.
• Solder and flux: solder is the metal that joins the seams, and flux helps it flow.
• Vitreous paint: glass paint that fuses permanently into the surface in a kiln.

"What are the black lines?" How a panel is held together

Those dark lines are usually metal, and they're the answer to the biggest question in stained glass: what holds all the pieces together? There are four main answers.

Technique	Best for	Skill level	Key tools
Lead came	Architectural panels and traditional windows	Advanced	Lead came, glass, soldering tools, cement
Copper foil	Suncatchers, lampshades, and fine details	Beginner to intermediate	Copper foil, soldering tools, glass cutter
Fused glass	Jewelry, tiles, and layered decorative pieces	Beginner to intermediate	Compatible glass, kiln, kiln shelves
Painted and fired	Faces, lettering, shading, and fine imagery	Intermediate	Vitreous paint, brushes, kiln

Lead came

Lead came works like a metal picture frame with many borders inside it. The glass slides into the channels, and the came is soldered where the strips meet. The dark lead lines become part of the design, which is why they're so easy to spot in a church or old house window.

Copper foil

Copper foil is like wrapping the edge of every puzzle piece in metal tape. The wrapped pieces sit edge to edge and are soldered along every seam, which allows tight curves and small details. It's the method behind Tiffany-style lamps.

Fused and painted glass

Fused glass stacks compatible pieces and heats them in a kiln until they bond, with no metal lines at all. Painted-and-fired glass puts paint on the surface first, then the kiln fuses it to the glass so it can't rub or wash off. If your child spots a face or words in a window, that part was painted.

In kid words: the black lines are the glue. They're metal strips that hold every colored piece in its place, like the lines in a coloring book that keep each color in its own space.

"How do they know where each piece goes?" From drawing to window

A professional panel starts at a drawing table. The maker draws the cartoon at the window's real size and gives every section a number, a color note, and sometimes an arrow showing which way the streaks in the glass should run. Those marks work like addresses, keeping each piece in its proper place, much like a paint-by-number page.

The pattern is transferred to the glass, and the cutter follows it in one steady stroke. That stroke creates a controlled weakness, allowing the glass to break along the planned path. Each piece is then trimmed or ground until it sits cleanly against its neighbors without being forced, because even joints spread stress across the whole panel.

Pieces that need painted detail go into a kiln, where the heat fuses the paint into the surface of the glass. Then the pieces are soldered together. A leaded panel is also cemented, with a putty-like compound brushed under the lead to firm it up and seal the gaps. Large windows get extra support, such as metal bars, before they're framed and installed.

"Can we make one?" Trying it at home

That's usually the question that comes after "how." Children can't cut or solder glass, but they can do the part that makes stained glass what it is. That means choosing a design, dividing it into sections, picking a color for each one, and seeing how it changes in the light. Both versions below follow the same steps a studio does.

With paper from the craft drawer

1. Pick a design. Choose a few large, simple shapes, such as a sun, a leaf, or a star. A quick trial on scrap paper shows problems early, just as it does in a studio.
2. Make the frame. Draw it on black cardstock and have an adult cut out the openings. The black lines play the part of the lead.
3. Fill the color. Back each opening with colored tissue paper or cellophane.
4. Hang it. Tape it to a sunny window and watch which colors change most as the light moves.

With a suncatcher that lasts

Tissue paper fades in a sunny window. For a piece your child can keep in the window, the Stained Glass Deco Kit reaches the same look by a different route. A child fills the sections of a ready-made metal frame with small colored plastic beads, following the picture guide, with the frame laid on a foil-covered baking tray. An adult then bakes it in a household oven (follow the kit's instruction sheet, which says 375°F for 25 to 30 minutes), and the beads melt into one translucent panel that hangs from a chain in a window.

There's no glass and nothing is cut, but it answers the same question your child started with. The metal frame does the job lead came does in a real window, outlining every section and holding the color in place, and the melted beads let the light through the way colored glass does. The design decisions are the child's, and the oven is the adult's.

Family rule: Let children make the visual decisions, while adults handle heat, sharp tools, and final placement.

Weighing a few options before you buy? Our guide to comparing stained glass kits by age and type covers what to look for.

Staying safe

Cutting glass, working with lead, soldering, and firing a kiln are adult trades with real hazards, including sharp edges, lead exposure, hot metal, and very hot kilns. That's exactly why the home versions use paper or plastic instead, and it's a good thing to explain if your child asks why they can't use real glass.

• The oven step is for adults. An adult puts the tray in, takes it out with oven mitts, and sets it where children can't reach.
• Let it cool completely. The panel makes popping sounds as it cools, which is normal. The sheet says to allow about ten minutes, and nobody touches it until it's fully cool.
• Don't overbake. Overbaking burns the beads, so stick to the sheet's time and keep the kitchen aired out.
• Loose beads are a choking hazard. Keep toddlers, younger siblings, and pets away from the table, and sweep up and bag any strays before you walk away.
• Scissors and craft knives stay with adults for cutting the openings in the paper version.

Frequently asked questions

What is stained glass actually made of?

Ordinary glass with metal oxides added while it's molten, such as copper for ruby or cobalt for blue. The color is inside the material, which is why it holds as light passes through.

Is the color painted on, or is it in the glass?

Usually it's in the glass. Paint is used for details like faces and lettering, and it's fired in a kiln so it becomes part of the surface.

What is the difference between lead came and copper foil?

Lead came is a channel-shaped strip the glass slots into, suited to large panels. Copper foil wraps each piece's edge so the pieces can be soldered directly together, which allows smaller, more detailed work.

What is a cartoon in stained glass?

The full-size working drawing the panel is built from. Every section is numbered and marked with its color, so each cut piece returns to the right place.

How long does it take to make a stained glass window?

A small decorative panel takes weeks. A large architectural window can take months, because every piece is cut, fitted, and often painted and fired one at a time.

Can kids make real stained glass?

Not the cutting and soldering, which are adult work. Children can do everything else, from choosing the design to picking colors and seeing how it looks in the light, with paper and cellophane or a bead kit where an adult handles the oven.

The next time sunlight comes through a stained glass window, your child will know what they're looking at: color baked into glass, cut to a drawing, and held together by those dark lines. Better still, they'll know they can make one. If they like knowing how things work, we've also explained how a music box works, what makes a toy robot move, and how magnets work. When you're ready for a project to make together, browse our craft kits.