A Guide to Heart Glass Shapes in 5 Basic Glass Heart Designs

A Guide to Heart Glass Shapes in 5 Basic Glass Heart Designs

The heart shape symbol is a two-dimensional geometric shape and there are 5 basic glass shapes where all other styles originate (described below). Here at Go Fusing we offer all 5 glass precut designs in a COE 96 Fusible Glass Precut Heart Shape from 3 mm thick sheet glass or made from a glass powder Wafer at 1 mm thick. 

In reality, the Heart Shape Symbol does not look anything like the actual organic heart shape! Yet, we humans associate the heart shape with our own organic heart and our emotional characteristics like love and passion. Precut or Drawn Heart Shapes are "the" symbol for Valentine's Day all though the basic heart symbol is documented as far back as the 1400 AD.

Today there are 5 variations of the basic Heart Shape. Hearts are similar to a triangle with a point at the bottom end. The Heart is composed of two circular arches at the top and two perpendicular lines straight lines from the arches and meets at a tapering point, called the apex. With these two basic geometric shapes many heart styles used by glass artist can be created from:

Traditional Precut Glass Heart Shape

In a  Traditional Precut Glass Heart Shape both the heart-shaped curves and lines are symmetrical you have a more traditional style of heart.

Inflated Precut Glass Heart Shape

Typically the  Inflated Precut Glass Heart Shape Arches are enlarged. The center V between the two arches and the point at the bottom is held stationary but each of the arches is pulled upward and outward. Giving the impression the heart has been inflated like a balloon.

Ruffle Precut Glass Heart Shape

Usually the  Ruffle Precut Glass Heart Shape is a basic traditional heart but every line, curved and straight, has a consistent undulating rise and fall of the line at consistent intervals. Some variations of this add a lace

Elongated Precut Glass Heart Shape

The Elongate Heart Precut Glass Heart Shape design starts with keeping the traditional heart-shaped arches at the top but the point where the two perpendicular lines meet at the bottom are stretched so they extend beyond the original systematical form.

Stylized Precut Heart Shape

This interesting shape is primarily it is really a revision of the Elongated Heart Shape. Typically the point at the bottom of the heart symbol is held stationary and only one of either of the circular arches is pulled up and outward or down and inward. This causes one side of the heart symbol to be stretched and/or bent in a disproportionate amount to the opposite side of the overall heart. In other words, the two sides of the heart are no longer proportionate or even dimensions.

Regardless if you are using fusible precut glass shapes or designing a Valentine Day’s Card, determining what style of Heart Shape to used when glass fusing is up to if you wish to subliminally project a feeling or you just like the way it looks. One of the best things of pre cut glass is there is no need to cut glass, no glass supplies or fusing supplies, just pop them in your kiln or microwave kiln.

Example: An Inflated Heart Shape can project Happiness or Pride compared to a Stylized heart maybe used just because you like the offset feeling of the look.

Precut Fusible Glass Shapes and Kiln Firing 

When it comes to Fusing Glass, what matters is the temperature, how hot and how long you fire the precut glass in your kiln.  If you are using a fusible precut glass that is a 3 mm thick Glass Shape versus a 1 mm thick Glass Wafer Shape, then your kiln firing schedule is critical. 

It is very tempting and easy to use preset kiln firing schedules which are meant for 3 mm sheet glass in your kiln because you can set and forget until it is time to open the kiln. BUT… I would highly encourage you to think about what you want the final Heart Shape to look like.

Here are the common mistakes when kiln firing Precut Glass Shapes in general:

Over firing as at a Full Fuse:

You purchased a Precut Glass Shape because you like the shape but if you just crank up the kiln to a full fuse remember, as all 3mm sheet glass reaches the molten temperature of a full fuse, it is like lava and it moves and flows. So you will loose the crisp edges of your pre cuts in any shape. In fact, glass likes to puddle at a full fuse, pre cuts in any form of glass shapes affects the results, even a glass circle will end up as a ball when fired too long. Any coe precut glass, stained glass, coe 90 or 96 will behave the same when overfired. At a max temperature, you may have started with a 3 mm thick precut glass shape but it can end up thicker and no longer resembles the fusible precut glass shape you bought. The only precut shape that is fairly safe to full fused is a glass circle just don't fire it too long or you will also get a glass pebble ball. Transparent glass or opalescent glass are equally susceptible to over firing.

3 mm Glass Shape Recommendations

Fire a 3mm Precut Glass Heart or any other non circle up to a Tack, Contour or even a Slump fuse schedule depending upon how crisp you want to retain the initial shape. This is true regardless of the coe glass being use.

Remember a 3 mm thick precut shape stacked on top of another,of compatible COE glass, will now be 6 mm thick and heavier. If the base glass is not the same shape or size, you will always have a bump in the surface layer of glass from the top shape. To avoid the bump, try to fill in in clear frit around the shape and outward covering the entire surface of the base class.

For a Wafer Shape,, at 1 mm thick, and possibly a thin Glass Clay Shape, there should be no bump as a wafer shape has an advantage of allowing the powders to flatten out onto the surface of the base glass and give you a lighter and more even surface of the fused glass artwork.

Ramping up and Firing to Fast: 

All though a 3mm thick Precut Glass Shape is not sensitive to this issue, Wafer Shapes are only 1 mm thick. Using a preset kiln schedule that came with you kiln controller from the manufacture will not make you successful with glass powdered Wafer shapes or Glass Clay shapes. Because Glass Wafers and Glass Clay are made with adhesives and binders, a slow ramp up speed is critical to allow time for the binders to burn off. If you ramp up to fast, you run the risk of the burn off binder fumes or residue to be captured between the glass and leaving brown or black impurties to be permanently captured between the glass layers. So a preprogrammed ramping speed for 3 mm thick precut glass shape made from cuttings of sheet glass will not work. (see firing schedule below).

You must ramp up your kiln firing schedule slowly to allow binders and adhesives to burn off and this will avoid the glass melting to fast and capturing the burn off fumes between your layers of glass.  So slow it down!

1 mm Wafer Shape Recommendations:

To fire Precut Glass Wafer Shapes or Glass Clay Shapes modify your ramping up schedule to this:
- Ramp Up: 200 dph at 1000 dF hold 60 minutes.
- 2nd Stage: 50 dph at 1225 dF hold 25 minutes.

Regardless if you are kiln firing Precut Glass Shaped Hearts made from 3 mm thick sheet glass or 1 mm thick Wafer Heart Shape made with glass powder or even one made from glass clay, we hope you find the information provided in this article make you more successful in retaining the desired shape of your precuts and to get the desired results in you final artwork!

Go Fusing today and Enjoy!