Better contact

I bought a new vacuum cleaner:)



I made a silicone sheet jig. The silicone sheet sometimes wimples while heating because it gets longer by heat. This jig gives a little tension which avoids wimpling.


I got perfectly saturated consistent black! For money savings, most of these caps are already printed test chart. Blank keycaps are expensive in my budget.


Printed on blank keycaps:

Perfectly saturated consistent black. I've gained some confidence with my method.

But I've found printing misalignment. I feel my keycap mount is not stable enough. In principle, plaster is highly stable. Aging is required? I went wrong while alignment? Anyhow, I have a plan to make new design keycap mount.

Contact is important

Today I've found the contact of dye-sub film and material is important for consistent result.



The inconsistency of black thickness is came from the inconsistency of the contact. I need better contact. My vacuum cleaner may be not enough...

Compensation of ink bleed

Now I'm trying to print black background and compensate ink bleed.

The image what I want to make:


What I printed to dye-sub transfer film:


What I've got:


A bit stronger compensation is required, but image sharpness will be lost more.

How to make a keycap mount: Part 3

Prepare test chart.


Microscope image:


Print the test chart and compensate each keycap's misalignment.


Microscope image:


Hmm, ink bleeds about 2 px (600 dpi). Some compensation is required, but this is a bit hard problem.

How to make a keycap mount: Part 2

Cast plaster.


Peel off OHP sheet.


Separate mask and base carefully.


Clean up mask's film side by file.


Drill air holes.


Calibrate printing image roughly.

How to make a keycap mount: Part 1

First, prepare alignment marks.

I used aluminium rivets.


Cramp with a vise and draw scribe lines.


Cut the trunk.


Prepare printing image and print it on OHP sheet.


Glue keycaps on the OHP sheet by glue gun.


Glue the alignment marks by gum.


Prepare mold. Seal up by Scotch tape.


Cast plaster. Reinforce by fiber material. I used nonwoven fabric for cooking.


Fill overhang by clay.


Give coat of dish soap as parting agent.


Continue to part 2...

PBT DSA keycaps

I got PBT keycaps. Signature Plastics' DSA profile.


I'll print Madoka runes on this set, white letter on black background. And I'll explain the process of making keycap mount step-by-step.

Background color and ink saturation

To print white letter, background color should be saturated. Another overlap test result:



I printed the same pattern (three color belts) twice with 90 degree rotation.

The belts are M100, C20 and C20M100 each (generally. My printer is home/office model, the so-called RGB printer. Cannot control ink by CMYK). M100 x M100 square shows little difference. This is because M100 is nearly saturated. M100 x C20M100 square is the same thing. C20 x C20 shows distinct difference. Because C20 is far from saturation.

C20M100 x C20M100 square shows, not very distinct, but noticable difference. It's because C20 ingredient is not saturated.

In the conclusion, every ingredients of the background color should be saturated.

In that case, background color is restricted to these colors at most?
CMYK
Light Cyan
Light Magenta
Light Black
Light Light Black
...and mix of them
(But I doubt that the light colors are simply diluted)

In some way, yes. If I can get spot color ink for dye-sub, the answer is no. But I couldn't find such thing yet.

But...

C20M100 x C20M100 overlap is not seriously noticable. It's OK if overlap is narrow enough.

(C20 background is impossible though, any way)

Unsaturated ink overlap test

Unsaturated ink overlap makes a result like photoshop's multiply.

White letter problem

Dye cannot print white. White letter is a problem.

Basically, the only one way is printing every colors except for white. If the problem is just for top side, everything OK... Not in reality.

Printing on five sides

I yet haven't tried to print on five sides, but it seems hard. In the case of top side only, I run 6 batches for full-set keys. Better instruments can reduce the burden dramatically, of course, but the investment is huge. According to my speculation, around $3,000 for 1 batch process instruments at least. Larger keycap mount enables larger batch, but it requires better accuracy and durability which costs much. I cannot believe my DIY plaster jig works well at such region.

One batch time is around 15 minutes. 1.5 hours for 6 batches. Good. But 1.5x5=7.5 hours? Oh...

If printing on only one or few keys, red ESC key for example, the burden is not so hard. 1.25 hours for 20 pcs of red ESC key, Good.

But there is another obstacle.

Ridge line gap and overlap

Ridge line of keycap is not so sharp. Two cases are possible: gap and overlap.

Gap makes white line on ridge line. Very awkward. Overlap makes deep color line if the ink is not saturated. Therefore two principles are required:

1. Make overlap rather than gap.

2. Ink should be saturated.

Principle 1 means printing margin management. It requires some effort but makes no restriction.

Principle 2 means the restriction of the color. Saturated by unmixed single dye will be OK. But if mixed? Overlapping makes deeper color until all contained dyes saturate? I should test it before I print white letter...

If things go well, the restriction of the color isn't practical restriction. White letter on pale color is not practical. By the way, to print black letter on colored background, simply dye the keycap before printing.

Black key

About black, the problem is much easier. Black is perfectly saturated and color matching is easy. If light, make deeper, finish.

So I can use easier dyeing process for non-lettered sides. I mean, paint black dye by brush, heat, and wash off the dye. It is yet a burden, but 30 minutes for full-set keys, I suppose.

Color calibration and RIP

I've got a conclusion about color calibration and RIP.

1. Make my printing data by Adobe RGB.

2. Google iPhone case printing shops which use 3D sublimation.

3. Ask them for print my data on their sublimation film and send the film me.

The reason:

My top priority is to avoid poor dither dots. It is accomplished by 6-color printer. Therefore I must use 6-color printer when I print picture.

Dye-sub ink available 6-color printer is not low end. Its color calibration is not easy and requires expensive devices, I think. Moreover, I may fail at all.

I can avoid the cost and risk by subcontracting to iPhone case printing shops. The price will be around $50 for 5 pcs A4 sheet, I suppose. I'll try enough by my low end printer, and use the iPhone case printing shop for final product.

My instruments

These are my instruments.

A part of vacuum former:


It consists of:
- Steel tray for cooking. $1. Bought from nearby shop.
- Waterworks pipe screw. $3. Bought from nearby shop.

I drilled the tray and glued the screw by glue gun.

The glue gun and the drill:




Common things I always have. You can buy enough things by $2 and $50.

A part of vacuum former:


Waterworks flexible pipe. $6. Bought from nearby shop. I connect a side to tray with screw, another to vacuum cleaner with duct tape.

The vacuum cleaner:)


A part of vacuum former:


Left is film side up, right is tray side up. They are plaster and I made them by casting and drilling.

Lego, burnt plaster and clay:


Lego: picked from garbage dump ago.
Burnt plaster: Enough quantity by $10. Bought from nearby shop.
Clay: Enough by $3. Bought from nearby shop.

Lego is nice to make mold frame. Clay is for molding keycap mount base. If you forget filling the keycap's overhang, keycap mount base doesn't come off. I did the mistake once...

Plaster casting is complicated process a bit. I recommend you to learn well first. FYI, I used dish soap as parting agent.

Inkjet printer:


$100 with non-oem dye-sub ink. Bought from a seller in Japan. I don't know what ink exactly, but very common things, I suppose.

Heat gun:


Very common thing. $20. Bought from Amazon.co.jp.

Pyrometer for temperature control:


$16. Bought from Amazon.co.jp. But mine is too narrow range. I recommend you over 200℃ ready model, $20.

Up to this point, instruments are common things. Non-oem dye-sub ink is not uncommon. Search Amazon.com.

From here, special stuffs.

Silicone rubber sheet:


The photo's is cut to fit keycap mount. Originally it was A3 size and I bought by 10 pcs set from Shenzhen Basya via Aliexpress. The 10 pcs set price is... $95. I have 9 pcs expensive sheet purposelessly...

Silicone rubber sheet is a problem because it should be very soft. I bought some other sheets, but they are not as soft as Shenzhen Basya's. I recommend you to get 3D sublimation machine's sheet, if not Shenzhen Basya's.

Sublimation film:


The photo's is printed and cut. Originally A4 size.

The film is a problem, too.

First, I bought it from Shenzhen Basya. But now, they stop selling the item. You can find some alternatives at Aliexpress by searching 3D sublimation film, but I hear, gold film is not as good as transparent one.

Second, the film is expensive. I bought it as 100 pcs set by $200... Alternatives are about the same as expensive, too.

Keycap puller:


WASD Keyboard's. An accessory of their blank keycaps.