Archive for the ‘Picture Framing’ Category

The Types of Wood Used in Making Picture Frames

March 13, 2011 1 comment
Wood Types in Picture Framing

Picture frame mouldings come from a variety of different trees

The picture framing industry has long sought to provide its customers good value as well as a range of high quality mouldings.  To do so, it has sourced wood harvested from a wide variety of trees.  Broadly speaking, however, picture frame mouldings can be gathered under two headings: hardwood frames and softwood frames.  But as you are about to find out, it’s a little more complicated than that.

Hardwood frames and softwood frames.  Hmm, this would seem to speak to the fact that one is made of a harder, more difficult to work wood, and the other is more soft and yielding.  Well, um… not quite.  In fact, the designations don’t always have to do with how hard or dense the wood is.  For example, balsa wood – wait for it – is a hard wood, as is basswood, one of the most common woods used in making picture frames.

The one thing that all hardwood trees have in common is that their seeds have a covering, like an apple, acorn or walnut.  Softwood trees by comparison drop cover-less seeds, like pine trees.  Hardwood trees are typically deciduous trees which means they lose their leaves in the winter time.  Softwood trees are more commonly evergreens.

While we can say that not all hardwoods are hard and dense, we can also say that the hardest and densest of woods are indeed hardwoods, and this is where the confusion comes in.  In picture framing the terms are often used to refer to the workability of the wood rather than the strict designation.  So basswood frames are often referred to as softwood frames, as opposed to oak and maple, which are universally acknowledged to be hardwood due to their density and stability.

To confuse matters further, many commercial frame mouldings are made of basswood or ramin – both soft hardwoods – but have a veneer meant to mimic an even harder wood like cherry, walnut or maple.  In purchasing a picture frame you will want to stay alert to words like “finish”, as in “walnut finish frames”.  This probably means a ramin frame with a walnut finish.

Hardwoods are tough, hard-wearing woods that resist dents and scratches.  One way to tell a hardwood moulding from a softwood moulding is to scratch it with your fingernail.  If it doesn’t scratch easily, it’s likely a hardwood.

Hardwoods are generally thought to be more attractive than softwoods as they have well-defined grain patterns.  But truly dense hardwoods like oak, maple, hickory and teak can be a struggle to saw, sand and nail.  Softwoods, on the other hand, are much easier to work but are more prone to warping and can ooze sap.

In recent years most commercial picture frame mouldings have been made from soft hardwoods imported from Southeast Asia, specifically Indonesia, where cheap, easy-to-work ramin and basswood are the lumbers of choice.  Even when the mouldings are sourced through China, the Chinese are often getting the moulding from Southeast Asia.  This is an issue as the Indonesians do not practice sustainability and deforestation is a growing problem in Indonesia.

Recently the furniture and picture framing industries have begun looking to hybrid poplar, grown in North America, made from black cottonwood and eastern cottonwood, for its better sustainability.  But this has not yet ramped up.

The most common soft hardwoods used in picture framing are basswood, ramin, obeche and mahogany. The most common dense hardwoods are oak, walnut, cherry and ash.  The most common truly soft softwoods are pine, redwood and cedar.

Whichever moulding you choose, remember that the picture framing industry has always endeavored to provide a low cost, easy to work wood that has the beauty and character to enhance fine works of art.  In this they have largely succeeded.  ♦

Author and Client:  This article was written by Malcolm Logan for Logan Graphic Products, Inc.


How to Cut a Flawless Mat for Picture Framing

December 1, 2010 Leave a comment
Cutting a Flawless Mat

A mat cutter is an instrument that can produce perfect results - if you know how to use it properly.

To cut a flawless mat you must let go of the idea that there is anything automatic about mat cutting.  To the extent that a “machine” provides a predictable result, flawlessly, without the know-how of the operator, a mat cutting machine doesn’t exist.  Cutting a mat is, to a great degree, a craft, requiring an understanding of the material as well as the know-how to use the tools properly.  A mat cutter is an instrument in the hands of a skilled practitioner.

Mat board is a dense stack of paper, several laminates thick held together with glue.  The blade used to cut it is very thin.  It must be, because if the blade was too thick it would tear the paper.  Yet because it’s so thin it has a tendency to flex, and if the blade flexes, the line of the cut will waver.

This common flaw is most evident at the beginning of the cut where the blade first penetrates the mat and is seen as a slight dip or “hook” near the corner.  To help alleviate the problem some mat cutters are designed so the blade passes through a narrow slot which keeps the blade rigid to the point of penetration.  Others have a tiny screw that can be tightened against the face of the blade to stiffen it.

Blade Flex

A mat cutting blade can flex if it's cutting too deeply.

Despite these helpful features, blade flex can still occur if the cutting head is twisted, rocked or torqued during the cut.  It is ultimately up to the operator to make sure consistent directional pressure is applied to the cutting head throughout the cut.

Even with that precaution, blade flex can still occur if the cut is too deep.  In mat cutting, a scrap piece of mat board called a backing sheet is used under the mat when cutting.  When the cut is too deep, the blade penetrates through the subject mat board and halfway or more through the backing sheet.  This puts excess drag on the blade, leading to blade flex.  Adjusting the depth so it just scratches the surface of the backing sheet will alleviate the issue.

Once the backing sheet has a lot of scores in it, it should be replaced.  Otherwise the blade can catch in previous scores and track on them, flexing out of line.  Any left over or remnant of mat board can be used as a fresh backing sheet.

A dull blade can also lead to blade flex.  When the blade is new it passes through the mat board with little resistance, but as it becomes dull it drags more and more.  The more it drags, the more it flexes.

If blade flex occurs, three steps should be followed to eliminate it.  Change the blade depth, change the backing sheet and change the blade.

The Blade Penetrates the mat at an angle.

The blade penetrates the mat at an angle. This realization is important to understanding over cuts.

Rough or ragged edges are another common problem in mat cutting.  Different manifestations of the problem can be detected by different feels in the cut.  If the cut feels crunchy, the blade is dented or chipped and must be changed.  If the cut feels like it’s pulling or tugging slightly, you are cutting repeatedly in the same score on the backing sheet and the backing sheet must be moved slightly one way or another to find a fresh place.

Patchy cutting through or failing to cut through consistently over the length of the cut indicates a chipped blade (you’ve lost the last little bit at the tip that allows consistent penetration).  Change the blade.  Alternatively, the problem could be the result of a depth setting that is too shallow.  Adjust the blade depth.

Proper blade depth is the key to eliminating many of the common flaws seen in mat cutting.  Unbeknownst to most novice framers, mat board varies in thickness.  Even within a so-called line of “standard thickness” mat board, minor variations in thickness are common due to the different thickness of the face papers.  These different thicknesses are largely responsible for the most bedeviling issue in mat cutting, a seeming inability to stop precisely and consistently in the corners, leading to over cuts and under cuts.

All mat cutting blades penetrate the mat at an oblique angle, meaning that they penetrate the back of the mat at a point further back than they emerge from the face.  If the mat board is thicker, it takes the blade longer to emerge, leading to under cuts.  If the mat board is thinner, the blade emerges earlier, leading to over cuts.

Compensate by moving the indicator line

On mat cutters that hide the point of penetration in a slot, compensate by moving the indicator line.

On most mat cutters, it is possible to set the blade depth precisely so the blade emerges precisely at the corner each time.  However, everything changes when you change to a different color or style of mat board, as it may be thicker or thinner.

Rather than struggle to readjust the blade depth each time, most framers employ some form of visual compensation to cope with the issue.  The most common approach is to simply watch the point of penetration relative to the pencil lines, moving the point of penetration forward or back slightly to compensate.  On mat cutters where the blade cuts through a slot before penetrating, the same adjustment can be accomplished by moving the cutting head’s indicator line forward or back of the pencil line.

The trick, of course, is in knowing how far to move it.  Is it a sixteenth of an inch?  Is it a thirty-second?  Well, that depends on the degree of the over cut (or under cut).  So what’s called for here is a test cut to diagnose the degree of the over cut / under cut.  If you are willing to make six cuts rather than just four, you can get perfect corners on your mats fairly consistently.  Here’s what you do…

If it’s your intention, for example, to cut a mat with 2 inch borders, start out by drawing your borders slightly wider, say 2½ inches.  Mark out all four pencil lines but only make two adjoining cuts, starting and stopping on the lines you’ve drawn.  Then turn the mat over and diagnose the over cut / under cut situation.  Now readjust to the borders you actually want and use the diagnosis from the test cuts to move the cutting head slightly forward or back to achieve the best possible corners.

Mat cutters with automatic production stops provide a third way to compensate for over cuts / under cuts.  Automatic production stops are metal blocks that lock down on scales.  They stop the cutting head automatically at the point of contact.  If you are using automatic production stops and see that you are getting a 1/16th inch over cut, you will naturally move the stop by 1/16th inch on the scale to eliminate it.

Automatic production stops may be the only things that are automatic on most mat cutters.  Even computerized mat cutters require some knowledge and input on the part of the operator to produce good quality results consistently.

Cutting a flawless mat is more of a craft than most people assume.  Understanding the materials and tools are the key.  But if you can cut a mat that doesn’t exhibit over cuts or under cuts, a mat where the edges are sharp and clean, and a mat that has a consistent 45-degree beveled edge without any wavering in the line of the cut, you have, by definition, cut a flawless mat.  And you have become a skilled practitioner with good knowledge of the instrument you are using.