The direction of the wood grain for your pyrography blanks is determined by the direction in which the slab was cut from the original log. A tree adds a new layer of growth each year, made up of vascular bundles which are similar to open drinking straws that move the fluid through the tree. How those vascular bundles are aligned on your blank determines the wood grain direction.
The grain direction of your wood blank does affect your pyrography strokes and tonal values.
End-grain cuts, as the top oval, often burns unevenly because of the open grain and growth rings.
The rectangular slab, shown in the back, is cut with the grain of the wood,
making it perfect for fine detailing and multiple tonal value work.
The top, oval basswood board is an end-grain slice that is cut across the circumference of the log, cutting all of the vascular bundle straws. Imagine looking straight down onto a hand full of drinking straws. What you see is the cut, open tops of those straws. End grain burns can appear spotty, and have irregular fine line detailing because of the end grain and growth ring openings.
The background board is cut with the grain of the wood, meaning that the tree was milled vertically from root to tip. Here you would see that same hand full of drinking straws from the side, showing the full, long length of the outer straws.
Both samples shown are called live-edge or live-bark cuts, meaning the outer, newest growth rings and the bark have been left on the board as a decorative frame for your work.
SANDING THE WOOD BLANK
Sand paper from 220 to 320 grit
Foam core fingernail files
Heavy brown kraft paper
The smoother your wood surface the finer and straighter your detailing lines
can be worked. Always sand with the grain of the wood using progressively finer grit papers.
End with a good polishing of the wood surface using heavy-weight kraft paper.
Your wood surfaces will need a light sanding to create a smooth surface for the burning. Use fine grit paper, 220 to 320 grit, to remove the fine ridges and loose fibers on the wood. Coarser sand paper, lower than 220 grit, can leave sanding lines that can affect how the quality of your burn lines. Even fine ridges will cause your tool tip to skip or move as you pull the stroke resulting in uneven or non-straight lines.
Sanding pads have a foam core and are flexible making them great for curved surfaces as on a wood plate or the routed edge of a plaque. Available at your local drug store foam core fingernail files are a nice addition to your tool kit. They come in a variety of grits and are excellent for working deep carved detail areas of a wood shape. Foam nail files can also be used to clean your one temperature brass tips.
Bring with your coarse sand paper and work through to your finest. Always work any sanding device or tool with the grain of the wood to avoid creating fine scratches in the surface. For our photo sample the wood is being sanded in a circular motion to match the growth rings of the end-grain slab.
Heavy brown kraft paper as a large grocery store paper bag makes an extremely fine grit sanding tool and is often my final sanding media. Remove all the sanding dust with a clean, lint-free cloth before you begin your next steps.