What is Glaze?
Contrary to popular belief, decorative painted glaze does not refer to shine or an otherwise varnished surface. Although spelled and pronounced the same as in “glazed” donuts, “glazed eyes” or “glazed” ceramics, in our context glaze refers to an actual product that enables translucency of color, i.e. the ability to see one color through another without the two blending or worrying about an underneath color lost to top color opacity. Through the use of glaze, we are able to achieve remarkable dimension, optical texture, depth and beauty. Depending on the type of glaze, how it is pigmented (colored) and the way it is applied and manipulated, the resultant look can range from flat chalkiness to a rich 3-dimensional effect.
What most people associate with the term glaze is a material that creates a shiny surface. To achieve that, we use “topcoats”.
In general, a painted glaze finish is a randomly patterned, optically textured result. The choice of colors combined with the method of application can yield effects ranging from soft, indistinct movements of color to something more defined and busy.
The basic components of a glazed finish are a) the basecoat and b) the foreground color (the glaze mixture itself).
Choice of basecoat is meaningful. As the base will be visible through the translucent glaze, the impact of its color is important in the way you want the overall look to be. Base color influences resulting contrast, color temperature, value (darkness/lightness) and the mood these yield. White paint is not always the right choice, and in fact will usually produce an overly cool effect.
The process of glazing basically involves applying a liquid glaze over a dried basecoat and sliding/moving the glaze around depositing it in shapes, patterns and areas of thickness/thinness that creates infinite areas and amounts of color density. The result is that of many shades of the glaze, the base color and the combination of the two (one seen through the other), conveying a dimensional look. In order to facilitate the “sliding” of the glaze, it is important that the basecoat paint be a sheen other than flat, which is too absorbent. An eggshell finish is preferable and provides a reasonably well sealed surface.
The glaze itself is composed of two materials: glazing liquid and colorant, each purchased separately. Glazing liquid is a colorless (when dry) material that is basically the primary component of paint without any fillers. It is analogous to the plasma component of blood. A standard simple glaze consists of 4 parts glazing liquid mixed with 1 part colorant, usually any interior house paint. Oil-based glazes are made with oil-based glazing liquid and oil-based paint, and waterborne glazes use latex-based glazing liquid and latex paint. While different and more sophisticated glaze mixtures can be created in order to achieve different effects, this basic mix is what is used by many craftsmen as well as amateurs and at minimum cost. Its results are limited by comparison to the advanced materials, but will develop beautiful results if used properly. Professionals use glycerin-based glazes, which are expensive and not readily available to the public.
A key difference among the types of glazing liquids and a factor in deciding among them is their “open”, or working time. A glaze with longer open time remains wet longer and is easier to work with and adjust (go back and remanipulate areas to correct or even out). A shorter open time glaze dries faster and can be more difficult to use. A longer open time glaze maintains a wet edge (see below) longer and is less subject to lap line problems.
One popular misconception about glazes is that by adding water (do not do this with oil-based glaze), the glaze will be thinned and its open time extended. Wrong. Water, due to its evaporation rate, can hasten drying time and work oppositely to what is expected. Try using a commercially available “paint extender” if necessary, but even this will not magically provide a big difference. If open time is an issue, concentrate on developing your glazing speed and wet edge control to compensate.
All techniques fall into one of two categories: “positive” versus “negative”. In positive glazing, glaze is applied via a given implement to a clean surface, the intention being to create and develop a pattern as the glaze is added. With negative glazing, the glaze is first applied without any specific patterning or manipulation, then partially removed from the surface with the remaining material forming the effect.
Positive glaze application is frequently done with a brush, sponge, stippler or other textured tool. Glaze removal is frequently accomplished with a sea sponge, clean rag, rolled rag, towel, plastic sheet, etc. The choice of implement and method result in different looks. No single finish is better or worse than another is; rather they are simply different.
Common terminology using the words “on” and “off”, e.g. sponging on, ragging off, etc., refers to the positive/negative techniques. Sponging on is equivalent to randomly applying glaze with a sponge, i.e. the positive method. Sponging off means randomly removing glaze from the surface with a sponge.
Don’t even think about glazing an entire wall in one fell swoop. For all the magical properties a glaze has, one that it does not is its ability to stay wet for as long as you think you need it to. Although different glazing media have different open or working time characteristics, all have limits. In order to develop a beautifully patterned glaze, manipulation must be done while the glaze is very wet. Beyond that, and it will stubbornly refuse to move across the surface they way you want it to, start to bind and dry, and spoil your well-planned effects prematurely.
The technical term for the unhappy results are “lap lines”, areas along the borders of adjacent glazing sections framing them out and in general making the finish look boxy and poorly executed. In all likelihood, if you try to spread out more glaze than you should, by the time you return to the starting point to manipulate it, it will have started to set up before you are ready for it to, and your best-laid plans are likely to fail. Time is not the only villain in this. Temperature and low humidity are as well.
The way to address this issue is to limit the amount of area you are trying to glaze at any one time. The answer? “Wet edges”. Section off limited areas you are trying to glaze; let’s say approximately 9 square feet. When applying the wet glaze, allow the outermost 6-inch margin to remain untouched (unmanipulated), thus staying “wet”. Touching and finessing glaze hastens its drying, which is what you want, but only where you want it to.
Move in a consistent pattern, setting up and glazing sections in a regular pattern, top to bottom, left to right (or vice versa). When setting up a section adjacent to one already worked one, overlap the wet edge of the earlier section with the new. The glaze should still be sufficiently malleable. A helpful way of ensuring success is to work with a helper. One of you (most likely the helper) will be responsible for applying fresh wet glaze to the next section to be manipulated, while the other (you) follow by doing such manipulation without delay.
Got lap lines even though you’ve done your best to prevent them? Add in more glaze (positive application) randomly near and about the visible defects, “walking” the glaze from noticeably poor areas toward and into adjacent ones in order to even out the effect. Coming back in with a water-wetted implement to help dissolve/thin/remove dried glaze may help. Experiment before trying this for real.
Beautiful effects can be achieved through the use of multiple color glazes. In its simplicity, straightforward glazing involves two colors: the base color and the glaze color. By using multiple glaze colors, varied effects are possible. Note however, it is easy to attempt this and wind up with something you are not pleased with if the glazes are overworked, i.e. the colors combine into a muddy mess. Ways to avoid this involve keeping areas of color distinct and only blending overlapping edges, and by applying the glaze colors in layers, allowing drying of the underlayer before adding the new. Remember that glaze’s translucency will allow underlayer colors to express through and not be covered up. Experiment on sample boards before trying this for real.
Applying Glaze in Layers Can Create Patterns
Geometric or linear patterns can be achieved by masking off areas of the basecoat with low-tack painter’s tape and glazing exposed areas (e.g. stripes, diamonds, etc.). Remove the tape as soon as possible afterward to avoid accidentally lifting the coat beneath. After drying, mask off glazed areas and apply a different color (unless the base color is chosen as the accent) to newly exposed basecoat. The process of using tape in this manner involves ensuring that your edges are good, straight and level (with respect to other lines). Avoid seepage or bleed-through under tape edges by burnishing the edges.
A multilayered effect, with glaze going over glaze, creates nice patterns. For example, to create a crosshatched linen weave, first apply and manipulate your glaze in one direction (e.g. vertically). Once dry, apply and manipulate the glaze in the other direction (horizontally). The result will be a nicely woven texture. While this can be accomplished in one step, by dragging both directions through one layer, the effect is not as nice, as the physical action of moving the wet glaze again will disrupt the clean lines created in the first pass. However, both methods produce interesting looks. Experiment first.
When ready to begin glazing, it is important to be prepared. Stopping or delaying completion of a logical section (e.g. a wall, from corner to corner) will yield unexpected and unsatisfactory results.
The concept of “sections” is important to note, as a large surface, i.e. an entire wall, cannot be properly glazed in one pass without risking early drying. The amount of time that glaze remains wet and able to be manipulated is referred to as “open” or “working” time.
Do-it-yourselfers are typically urged by books, videos, home improvement centers, cable TV shows and infomercials to create a glazed finish due to its “ease”. These sources may be more interested in selling product and supplies than in your confidence and ability. Like any other endeavor, ease is a relative term and is usually achieved through practice. While the materials involved in glazing are readily available, technique and experience are important as it is the lesser-discussed elements of a properly executed finish that demonstrate the difference between casual attempts and professional work, including: