True vs Simulated

What really is the difference between a True Prismatic and a Simulated

Prismatic letter?

Well, in both cases the letter sides are fully beveled.  In other words the

sides of the letters are sloped from the center ridge of the letter down

to the outer edge of the letter.  The difference between the two types

is all in the way the sides slope.

In a True Prismatic letter, the center ridge of the letter is all the same

height.  That means that the angle of the slope will be different

depending on how thick the stroke of the letter is at that point.  In

parts of the letter that are very thin (the serifs, for example) the slope

will be very steep - almost vertical.  In parts of the letter with thick

strokes, the angle will not be so steep.  You can see this in the photo of

the reversed letter "P" mold. 

Contact Us Contact Us

In a Simulated Prismatic letter, the slopes all have the same angle.  The

bevel still has to slope down to the letter edge, but what that means is

that the center ridge of the letter will have to change in altitude.  At the

widest strokes, the center ridge will be at maximum height.  At the thin

strokes, though, the center ridge will be much lower.  You can see this

in the two photos of the letter "R".  Notice how the height of the center

ridge varies.

The Final Analysis

Since the Simulated Prismatic letters have the same bevel angle, that

means they can be beveled with a standard "V"-shaped (conical) cutter.

 That means they can be fairly easily cut on a standard (3-axis) CNC

machine.  And that means they are relatively inexpensive.

On the other hand, a True Prismatic letter has constantly changing

angles of bevel.  Now, it is possible to mill these on a very expensive

(and more complicated) 5-axis CNC.  However, it will take a lot of time

because the machine will have to whittle away at the letter little by

little with a round-nosed bit.  And that means that even then there will

undoubtedly be mill marks and ridges that will have to be smoothed

off by hand.

The other option is to sculpt the letter out by hand in an easy-to-carve

medium such as HDU foam.

In either case, everything about the process of making True Prismatic

letters is time-consuming and thus more expensive. But the end result

is beautiful.

One Last Note

If a person wants to spend the effort, it is possible to design a font that

can be both True Prismatic and have a consistent bevel angle.  It's not

easy, but it can be done.  You can see an example in the photo and short

video of the polished aluminum number "3".

True vs Simulated

What really is the difference between a

True Prismatic and a Simulated Prismatic

letter?

Well, in both cases the letter sides are

fully beveled.  In other words the sides of

the letters are sloped from the center

ridge of the letter down to the outer edge

of the letter.  The difference between the

two types is all in the way the sides slope.

In a True Prismatic letter, the center ridge

of the letter is all the same height.  That

means that the angle of the slope will be

different depending on how thick the

stroke of the letter is at that point.  In

parts of the letter that are very thin (the

serifs, for example) the slope will be very

steep - almost vertical.  In parts of the

letter with thick strokes, the angle will not

be so steep.  You can see this in the photo

of the reversed letter "P" mold. 

In a Simulated Prismatic letter, the slopes all have the same

angle.  The bevel still has to slope down to the letter edge, but

what that means is that the center ridge of the letter will have

to change in altitude.  At the widest strokes, the center ridge

will be at maximum height.  At the thin strokes, though, the

center ridge will be much lower.  You can see this in the two

photos of the letter "R".  Notice how the height of the center

ridge varies.

The Final Analysis

Since the Simulated Prismatic letters have the same bevel

angle, that means they can be beveled with a standard "V"-

shaped (conical) cutter.  That means they can be fairly easily cut

on a standard (3-axis) CNC machine.  And that means they are

relatively inexpensive.

On the other hand, a True Prismatic letter has constantly

changing angles of bevel.  Now, it is possible to mill these on a

very expensive (and more complicated) 5-axis CNC.  However, it

will take a lot of time because the machine will have to whittle

away at the letter little by little with a round-nosed bit.  And that

means that even then there will undoubtedly be mill marks and

ridges that will have to be smoothed off by hand.

The other option is to sculpt the letter out by hand in an easy-

to-carve medium such as HDU foam.

In either case, everything about the process of making True

Prismatic letters is time-consuming and thus more expensive.

But the end result is beautiful.

One Last Note

If a person wants to spend the effort, it is possible to design a font

that can be both True Prismatic and have a consistent bevel angle.

 It's not easy, but it can be done.  You can see an example in the

photo and short video of the polished aluminum number "3".