Interesting big sized javanese keris

A. G. Maisey · 1st May 2010, 11:29 AM

Thanks Kai, I see what you're getting at now.

The only theorising that I've come across that relates to colour variations like is that when you get a wide variation in colour in the sap wood what you are looking at is the result of infection or damage to the tree. However, the way in which a log is sawn also has a huge effect on the final material. There is very often a wide colour variation between the sap wood and the heart wood in a tree.

The grain in the material of the example you have shown runs along the width of the wrongko top, from one end to the other. This means that it has been cut from a length of timber that has been sawn from the length of the trunk. A tree grows outwards from its core, so when you have a poor season, or a dry season, or a very good season, you can see this reflected in the growth rings that radiate from the core of the trunk.

Looking at the example that you have posted, Kai, I believe that what we are looking at is the result of the way in which the log was cut. There are several techniques used for cutting a log that will produce different effects in the grain shown in the final plank. The most common technique used to produce fancy grain material is called quarter sawing, a technique that results in the growth rings falling between 80 and 90 degrees to the face of the plank.This is done by first cutting the log into quartersthrough it, and then sawing each of those quarters longitudinally, producing increasingly smaller planks as you move to the outside of the quarter.

If we look at this example, we can see very pale wood at the extreme right, then moving left a darker wood, and at the far left a small touch of pale wood again. The pale wood would be sap wood, and the dark wood would be heart wood. The log that produced the material from which this wrongko was carved was sawn in a way to maximise the colour variation between heart wood and sap wood, and at the same time to maximise the chatoyant effect of the curly grain.

The image of a log cross section might clarify how this can be done.

Then again there are the other factors of genetics and disease.

1st May 2010, 11:29 AM	#34
A. G. Maisey Member Join Date: May 2006 Posts: 6,992	Thanks Kai, I see what you're getting at now. The only theorising that I've come across that relates to colour variations like is that when you get a wide variation in colour in the sap wood what you are looking at is the result of infection or damage to the tree. However, the way in which a log is sawn also has a huge effect on the final material. There is very often a wide colour variation between the sap wood and the heart wood in a tree. The grain in the material of the example you have shown runs along the width of the wrongko top, from one end to the other. This means that it has been cut from a length of timber that has been sawn from the length of the trunk. A tree grows outwards from its core, so when you have a poor season, or a dry season, or a very good season, you can see this reflected in the growth rings that radiate from the core of the trunk. Looking at the example that you have posted, Kai, I believe that what we are looking at is the result of the way in which the log was cut. There are several techniques used for cutting a log that will produce different effects in the grain shown in the final plank. The most common technique used to produce fancy grain material is called quarter sawing, a technique that results in the growth rings falling between 80 and 90 degrees to the face of the plank.This is done by first cutting the log into quartersthrough it, and then sawing each of those quarters longitudinally, producing increasingly smaller planks as you move to the outside of the quarter. If we look at this example, we can see very pale wood at the extreme right, then moving left a darker wood, and at the far left a small touch of pale wood again. The pale wood would be sap wood, and the dark wood would be heart wood. The log that produced the material from which this wrongko was carved was sawn in a way to maximise the colour variation between heart wood and sap wood, and at the same time to maximise the chatoyant effect of the curly grain. The image of a log cross section might clarify how this can be done. Then again there are the other factors of genetics and disease. Attached Images