Wednesday, August 10, 2011

Part II: How to Paint Lettering on Clear Glass

Painting lettering on glassware is similar to painting lettering on wood.  You need to start by choosing a font and a font size as described in Part I.  Of course, the lettering is likely to be much smaller on a wine glass than on a wooden sign.

Once you've printed your letters onto plain white paper, the steps are a bit different from lettering on wood.  A biggest difference is that there's no sealing or basecoating required on glass and there's no need to trace the letters onto the surface of the glass before painting! 

On the other hand there are some unique requirements for painting on glass.  Regular acrylic paint will quickly chip, peel, and wash off of the glass.  There are a variety of paints that were created to stand up to the wear and tear that glassware receives.  I've used a few of them and they all have their good points.  My favorite is FolkArt Enamel, but that doesn't necessarily mean that those paints are the best.  Whatever I write about here is based on my experience with FolkArt Enamel paints.  They are water-based, so the paint is easy to clean up with soap and water before it is cured.

FOOD CONTACT:
Another thing to consider is that, although most glass paint is classified as non-toxic, it isn't necessarily classified as food-safe.  Therefore, there should be about an inch at the top of a drinking glass that is left free of paint.  This also protects the design because acids from food, lipstick, and saliva can damage the paint over time.  If you want to paint on a clear glass plate to be used for food, you should paint the underside of the plate, so that food does not touch the paint.


GLASS PREPARATION: 
When you paint on glassware, you need to wash the item throroughly with warm soapy water and let it dry completely.  Just before you begin painting, wipe down the surface with alcohol.  Be VERY careful that you don't touch the surface where the paint will go after that or you'll leave fingerprints or oils from your skin that will interfere with the adhesion of the paint to the glass.  This can happen no matter how clean you think your hands are.


PAINT A FLAT-SIDED DRINKING GLASS:  Placing the lettering on a cylinder-shaped glass is fairly easy because the glass is the same width from top to bottom.
  1. Print the letters onto plain white paper.
  2. Cut away most of the excess paper around the outside of the lettering, but I don't recommend cutting the letters apart.  If you do that, you'll have to spend a lot of time lining up the letters.
  3. Clean the glass and wipe it down with alcohol.
  4. Place a rubber band at the top of the glass, about an inch down from the top.  Try to make the distance between the rubber band and the top of the glass somewhat even, but it doesn't need to be perfect.  Just eyeball it.  This is simply a guideline that will keep you from painting on the area where your lips will touch.
  5. Tape the paper onto the inside of the glass, below the rubber band, with the letters facing out.
  6. Paint the letters.  You'll most likely need to paint 2 or 3 THIN coats.  If you don't let paint dry between coats it will liftabout 15 to 20 minutes between coats should be fine.

PAINT A CURVED-SIDED DRINKING GLASS:  Placing the lettering on a curved drinking glass, or one that is not the same width from top to bottom can be a litttle more challenging.
  • Steps 1 through 5 are the same as for a flat-sided drinking glass above.
  • If the paper with the lettering doesn't conform to the curve of the glass, you can cut slits into the paper (don't cut into the letters themselves) so that the paper can move and spread, so that it will fit better.  Add more tape if necessary.
  • Paint the letters.  You'll most likely need to paint 2 or 3 THIN coats.  If you don't let paint dry between coats it will liftabout 15 to 20 minutes between coats should be fine. 
  • These instructions would also work for a curved glass bowl.

PAINT A FLAT GLASS PLATE:  The paint must be applied to the underneath surface of the plate so that it doesn't make contact with food
  1. Print the letters onto plain white paper and turn the paper over. 
  2. Retrace the letters with your Ultra Fine Sharpie on the back of the paper--those letters will be in "mirror image."  If you have a hard time seeing the already-traced letters on the front of the paper, just put your paper on a window with light behind it.  Put the already-traced letters against the glass while you retrace.
  3. Cut away most of the excess paper around the outside of the lettering, but I don't recommend cutting the letters apart.  If you do that, you'll have to spend a lot of time lining up the letters. 
  4. Clean the glass and wipe it down with alcohol.
  5. Tape the paper onto the TOP of the plate, on the eating surface, with the normal letters facing UP.  As you look at the tracing paper from the underneath surface of the plate, you will see the mirror image of the letters.  After you paint the letters, when you look at them from the top of the plate they will be normal.
  6. Paint the letters onto the underneath surface of the plate.  You'll be looking through the plate at the letters from above when you're finished.
  7. You'll most likely need to paint 2 or 3 THIN coats. If you don't let paint dry between coats it will liftabout 15 to 20 minutes between coats should be fine. 

TIPS:
  • Remember that you don't want to transfer fingerprints or oil from your skin onto the surface to be painted.  
  • Sometimes  you can fit your non-painting hand inside the glass to hold it.  Other times you can hold the glass by its stem or by the top edge above the rubber band.
  • Wearing a disposable latex glove on your non-dominant hand will allow you to hold the glass without transferring fingerprints or oil.  Be careful not to smudge wet paint with the glove.  I can almost guarantee that you won't like wearing a glove on the hand you paint with.
  • Remember when you're painting around the side of a drinking glass that you have to be careful not to smudge wet paint as you move around.  You can't lay the glass on it's side and roll it along as you paint, or you'll be rolling the paint onto your table and smudging the paint all over the glass.  Ask me how I know this!
  • One of the nicest things about painting on glass is that you can fix mistakes and smudges pretty easily before the paint has cured.  A cotton swab dipped in alcohol can often be used to remove a mistake.  There are also tools that look like paintbrushes with  the brush part replaced by rubber tips of various shapes.  They can be used to remove mistakes and smudges, but they work best when the paint is very wet. 
  • If the paint has dried, but is not yet cured, you can scrape off small mistakes with a toothpick or craft stick.  I don't recommend using a razor blade or craft knife because it can scratch the glass.
  • For more specific information on FolkArt Enamel paints, see these FAQs:  http://www.plaidonline.com/eduPDF/FolkArt%20Enamels%20FAQs.pdf
  • Even though the company says it's OK to put your painted items in the dishwasher, I prefer not to.  I definitely will not put a stem glass in the dishwasher.

CURING THE PAINT:

FolkArt Enamel paints must be cured so that they are permanent.  This can either be accomplished by air-drying them for 21 days or by baking them in your oven.  Some people swear that the paint is more durable if you bake it, but the manufacturer says that it's the same either way.  If you air-dry, that means you can't use or wash the item for 21 days.  Here are the instructions for baking:
  1. Let the paint dry for several hours.  If you bake it too soon, some of the paint can spread slightly and make clouds around your design.  I usually like to wait at least 8 hours.
  2. Remove the rubber bands!
  3. Put a cookie sheet into a COLD oven on a shelf that leaves enough room for your glassware.  You'll want to keep the glassware away from the heating element.
  4. Put the glassware on the cookie sheet in the still cold oven.  Don't let the painted areas touch the cookie sheet.  With most stemware, I like to turn the glasses upside down so that the top is against the cookie sheet.  This is just for stability.
  5. Turn the oven on to 350 degrees. 
  6. When the oven temperature reaches 350 degrees, set your timer for 30 minutes.
  7. After 30 minutes turn off the oven.  DO NOT OPEN THE OVEN DOOR.
  8. Let the glassware cool completely in the oven before you open the oven door.  I like to do my baking at night and leave the glass to cool overnight. 
  9. In the morning I remove the cooled and fully-cured glassware, one glass at a time.  If you try to remove the cookie sheet and all the glassware at once you're courting disaster.
If you open the oven door while the glass is still hot, cool air can hit the hot glass and crack or break it.  I'm told that the thinner the glass, the more likely it is to crack or break.  Some people say that even if you do everything right, you might lose a glass here or there because of flaws in the glass itself.  So far, I've never lost a glass to baking.


© Copyright 2011 Linda's Art Barn. All rights reserved.

2 comments:

  1. Thank you for the walk-through. We are trying to find a way to do some custom coffee cups on clear glass and may give this a try!

    ReplyDelete
  2. I'm glad this was useful to you, Wandering Path.

    ReplyDelete