Drawing to Scale
The whole idea behind creating scale drawings is to allow the drafter to create a drawing which is proportionately the same as the artifact it represents. Using a measuring device called a scale, we can create accurate drawings of both very large objects or very small objects and fit either on a standard size piece of paper.
Pronounced "Two to One"
DOUBLE SIZE :2 millimeters on paper =1 millimeter on the artifact
The drawing is twice as large as the artifact.
Pronounced "One to One"
FULL SIZE: 1 millimeter on paper =1 millimeter on the artifact
The drawing is the exact same size as the artifact.
Pronounced "One to Two"
HALF SIZE : 1 millimeter on paper =2 millimeters on the artifact
The drawing is half the size of the artifact.
Pronounced "One to Four"
QUARTER SIZE or 1 millimeter on paper= 4 millimeters on the drawing.
The drawing is one quarter the size of the artifact.
Often, scales are made in triangular form so that they can be marked with different scale ratios.
A triangular scale has 6 different ratios on it Here is what they look like:
Here are some metric scales:
Here's how to use them
These scales are all for large objects which would be drawn in meters. Let's start with the scale at the top labeled 1:200. Imagine that you lay this scale on your piece of paper and draw a line from the 0 to the number 5. You just drew a line that is 5 meters long at 1:200, meaning that if you measured this line on the paper, every millimeter would be equal to 200 millimeters on the original object you are drawing.
Now try the next scale down, the one labeled 1:500. Imagine that you lay the scale on the paper and draw a line from the 0 to 10m. (The m stands for meters) You just drew a line representing 10 meters at 1:500 scale. Try it with the 1:300 scale too. See how it works?
Scales are cheap, most under $10 and available through art supply stores. On line drafting supply catalogs are another good way to get them.
Now, if you're drawing small artifacts like effigies arrow points or pottery shards, remember you'll be drawing them either 1:1 (full size) or 2:1 (double size) or whatever is required. To draw 1:1 you can just use a standard metric ruler or 1:1 scale. To draw 2:1 just take a pencil and mark every other line on the ruler to remind you to use those marks and draw a line to each mark for every millimeter. Same thing for larger, like 4:1 you would mark every fourth millimeter and draw to the marks. Personally, I haven't had any luck finding scales that are 2:1, 4:1 etc… If anyone knows where to get them… please let me know!
Keeping your lines straight
Before you put pencil to paper, be sure you tape the corners of your paper to the drawing surface you are using. Only tape the corners because you can spend days on a detailed drawing and ruin the whole thing when you try to take it off the board!! When you tape the drawing on the surface, align the edge of the paper with a T-square.
Here is a T-square:
The cross piece of the T-square lays against the edge of your table or drawing surface (which must be straight by the way!!) Then align the edge of the paper with the long straight edge of the T-square and tape it into place. Use the T-square as your straight edge when you are drawing. Lean your pencil along the straight edge and you'll always have a straight line. Draw light reference lines which you can erase later to get the dimensions of the object.