A kick up is the indent found on the bottom of a wine bottle, also called a push up. These indents most likely strengthened the bottom of the bottle or formed a stable base on hand-blown bottles. Today, they are necessary only in sparkling wine bottles, which are inverted and stacked as part of the winemaking process.

A flat, round vessel with fine ribbing or patterned glass that's often green, a pitkin is made by blowing glass into a patterned mold, letting it cool, and then recoating it in hot glass. The bottle is then free blown or, as in this example, expanded inside a larger patterned mold to form a double pattern. Some of these pieces were made at Pitkin Glass Factory, in East Manchester, Connecticut.

Around 1880, glassmakers began adding manganese to glass to remove all traces of color. But when exposed to ultraviolet rays, the glass gradually turned purple; the longer the exposure, the deeper the color. The use of manganese stopped around 1915, as World War I began, because most of the mineral came from Germany.

Sick glass is glass corroded by water, which creates layers of etched iridescence. A little sickness isn't desirable, but a great deal of wear can create a beautiful, highly collectible bottle. Ancient bottles collected from archeological sites are pretty sick -- and lovely to look at.

This flask was made using a mold in which plates could be interchanged to custom-emboss its broad sides. The gap between the plates would create bands up to a 1/2 inch wide on its narrow sides, stopping at the neck.

Three-part molds include a single bottom piece and two top pieces that form the shoulders and neck. These were used mostly from 1870 to 1910.

Pharmacists stored medicine ready to be dispensed in these jars. The inside of the bottle's neck and the side of the stopper are etched to ensure a tight fit. The tab on the top was applied by hand.

This canning jar is from the 1920s. Its top is a variation on the lightning stopper used on old beer bottles. The adaptation from bottle to jar took seven years to perfect. This color was fairly common. Rare ones include black, milk glass, cobalt blue, and emerald green.

Some of today's gin bottles echo this squared-off shape, which was designed to fit into a special case for transport and storage. This one is from the 1860s or 1870s; it has a hand-applied lip.

These bottles contained store-bought pickles. They were made from 1880 to 1920 and were often embossed with a gothic pattern. Colors include aqua, dark green, and amber. The deeper the color and the more intricate the design, the more valuable the bottle. This one is about 10 inches tall.

This bottle, circa 1920, reads "McCormick & Co" and "Green Seal," and contained relish.

Before the Civil War, these bottles were large and round with a small neck, and held one to 10 gallons of liquid. The later versions were molded into a shape similar to that of a wine bottle. When in everyday use, they were often encased in wicker to protect the vessel from breaking.

An ink bottle required a stable base and an attractive design. The design of the octagonal umbrella bottle kept ink from going where it wasn't meant to go; these were popular from the 1820s to the 1880s. This model, made around 1845, was blown into a mold; its lip was applied by hand.

This fluted ketchup bottle from the late 19th century is similar in shape to today's ketchup bottles.

This jar, from the late 19th century, has added notches for holding olives. Most were cylindrical.

Before the invention of the tamper-resistant cap, bottles containing poison used texture, color, and type to broadcast that the substance within was lethal. In England and the United States, "poison" and "not to be taken" embossed on deep-green or blue bottles kept people from confusing health-giving tonics with life-taking toxins. In the United States, the standard design was cobalt blue and had a bumpy texture with the word "poison" embossed on it.

This mold-blown bottle, from the early 19th century, was for snuff (inhaled tobacco). Its seal would have been waxed-over cork. These are most commonly found in green or amber.

These bottles contained soda water or beer.

From the late 17th or early 18th century; used for wine. The glass contains many large, swirling bubbles, which appeal to collectors.

A plate-mold prescription bottle from the early 1900s.

These were over-the-counter medicines with a high alcohol content -- as high as 120 proof (higher than some vodkas). Most bitters bottles date from the second half of the 19th century. There are more than 1,000 known brands, and some of the vessels come in colorful glass. The most popular ones are figural, such as this fish.

An 1890s whiskey bottle. You can find these for about $5.

An old wine bottle. Its shape was originally designed for Bordeaux wines.

There are many ways to determine a bottle's age. One is the seam, an embossed line where the bottle's molds meet. Often, the older the bottle, the lower the seam ends. The line stopped where the mouth met the pressed section of the vessel. As techniques changed to make the process faster and more productive, more of the bottle would be formed by a mold. In the United States, molds were rarely used before the 1800s. Free-blown bottles have no seams, and almost all mold-blown bottles have some sort of seam.

Before the 1860s, seams would end where a bottle's shoulder met its neck.

From 1860 to 1880, the seam began to creep upward, as the ability to form part of the neck with a mold was developed.

From 1860 to 1880, the seam began to creep upward, as the ability to form part of the neck with a mold was developed.

The seam reaches a little farther up the neck.

The seam ends right below the lip.

The seam extends through the lip. The entire bottle is machine made.

Pontils are long rods that were used to hold bottles by the base so that the neck could be removed from the blowpipe and finished. It almost always left a mark at the center of a bottle's base. The number of utilitarian bottles baring pontil scars began to diminish during the late 1840s and ceased to exist by the mid-1890s.

Rough pontil marks are unfinished circular scars. They can be found on disposable vessels, such as soda bottles, that would have been considered mass produced for their time. The pontil would leave a circular scar. Before the Civil War, iron pontils were used. These left a trace of iron when removed. The appearance of this mark can increase the value of a bottle dramatically.

The bottoms of bottles to be used indefinitely, like apothecary jars, were ground, leaving a slight mark where the pontil scar had been.

Stamping wasn't possible on bottles made with pontils -- only machine-made vessels have stamps.